A student throws a set of keys vertically upward to her sorority sister, who is in a window 2.30 m above. The second student catches the keys 2.50 s later.
(a) With what initial velocity were the keys thrown?

It takes the cyclist 4 seconds to slow down.

Considering the acceleration is constant, we know that,

v² - u² = 2 a s

a = Δv / t

Δv  = v - u

where,

v = Final velocity

u = Initial velocity

s = Displacement

Δv = Rate of change of velocity

Given that,

u = 15 m /s

v = 3 m / s

s = 36 m

3² - 15² = 2 * a * 36

-216 / 72 = a

a = - 3 m / s²

a = ( v - u ) / t

- 3 = ( 3 - 15 ) / t

t = 4 sec

Rate of change of velocity is the velocity difference between initial and final velocity. It is denoted as Δv.

Therefore, it takes the cyclist 4 seconds to slow down.

To know more about Rate of change of velocity

https://brainly.com/question/4261938

#SPJ1

An 80 kg bicyclist is coasting down a long hill that has a 10° slope. The speed that a cyclist has eventually attained is mathematically given as

v = 26 meters per second. or v = 26 m/s

This is further explained below.

Generally, the equation for balancing the equation of Force is  mathematically given as

F1 = F2 + F3

Therefore

F3 = F1 - F2

Where

sinθ = sin(10) = 0.1736

and

cosθ = cos(10) = 0.9848

F1 = m g sinθ

F1=80 x 9.81  x 0.1736

F1= 136.24 N

F2 = μ m g cosθ

F2= 0.02 x 80 kg x 9.81 m/s2 x 0.9848

F2 = 15.46 N

Hence

F3 = F1 - F2

F3= 136.24 N - 15.46 N

F3= 120.78 N

In conclusion, The equation for is  mathematically given as

v = speed reached by a bicyclist

v= ((2 x F3 / (ρ x CD x A)) 0.5

Therefore

v = ((2 x 120.78 N / (1.2041 kg/m3 x 0.85 x 0.35))1/2

v= 25.97 m/s

v = 26 m/s

Read more about speed

https://brainly.com/question/28224010

#SPJ1

Complete Question

An 80 kg bicyclist is coasting down a long hill that has a 10 ∘ slope. His cross-section area is 0.35 m2, his drag coefficient is 0.85, his bicycle's coefficient of rolling friction is 0.02, and the air temperature is 20∘C.

What speed those he eventually reach?

The graph representing average speed ( s ) vs length ( m ) and square of average speed ( s² ) vs length ( m ) is shown in the image attached below.

The value of time period of three trials each for all three length are given. The average value of all the given time periods are found by using  

s = ( s1 + s2 + s3 ) / 3

Then the average time period is squared. In graph 1, the the length of pendulum ( y-axis ) is plotted against average time period ( x-axis ). In graph 2, the the length of pendulum ( y-axis ) is plotted against square of average time period ( x-axis ).

Therefore, the graph representing average speed ( s ) vs length ( m ) and square of average speed ( s² ) vs length ( m ) is shown in the image attached.

To know more about average time period

https://brainly.com/question/23406577

#SPJ1

By using Specific heat capacity, 741.76 x [tex]10^4[/tex]heat energy is needed to raise the temperature.

The amount of heat required to increase the temperature of 1 gram of a substance by 1 degree Celsius (°C) is known as the specific heat capacity.

The importance of specific heat capacity may be summed up as the quantity of energy needed to heat or cool an item of a given mass by a certain amount.

Given:

Mass of vat, mvat = 20kg

Mass of water, mwater = 3kg

ΔT = 90 – 10 = 80℃

Specific heat capacity of iron, Ciron = 450J/kg

Specific heat capacity of water, Cwater = 4186J/kg

To find:

Heat energy required, Q = ?

Formula:

C = Q / (m ΔT)

Calculations:

Q = mCΔT

Q = Qempty + Qwater

Q = (20 x 450 x 80) + (3 x 4186 x 80)

Q = 172.464 x [tex]10^4[/tex]J

Result:

Heat energy required is 172.464 x [tex]10^4[/tex]J

Learn more about Specific heat capacity here:

https://brainly.com/question/16952828

#SPJ9

Answer:

B

Explanation:

Gravity

Both the Moon's orbital period and its gravitational force on the Earth would be different.

Any two objects with mass are drawn together by the gravitational force. We refer to the gravitational force as attractive because it consistently seeks to draw masses together rather than pushing them apart. In fact, everything in the universe is pulling on everything else, including you.

The rise and fall of ocean tides is a result of the moon's gravitational effect. Their gravitational attraction to self-destructive behavior has been the focus of extensive research. of or pertaining to a strong movement or natural tendency toward something or someone.

To know more about mass :

https://brainly.com/question/19694949

#SPJ9

The best explanation of the energy in the circuit is, the energy in the battery was transformed into electrical energy, light energy, and heat energy.

option A is the correct answer

The law of conservation of energy states that the total energy of an isolated system remains constant, that is the total energy of the isolated system is said to be conserved over time.

According to the law of conservation of energy, energy can neither be created nor destroyed but can be converted from one form to another.

For instance, electrical energy can be converted into heat and light energy, mechanical energy can be converted into electrical energy, and vice versa, chemical energy can be converted into light and heat energy.

Thus, when she finds that the battery no longer has a charge, the best explanation of the energy in the circuit would be the energy in the battery was transformed into electrical energy, light energy, and heat energy.

Learn more about conservation of energy here: https://brainly.com/question/166559

#SPJ1

Answer:

Explanation:

It's A I got this question wrong twice and I got it correct when I clicked A. Hope this helps!

The ball rolling down the hill has an acceleration of 3.5 [tex]m/s^2[/tex].

Acceleration refers to the rate at which an object's velocity with regard to time changes. An object's velocity might alter depending on whether it moves faster or slower or in a different direction.

Given:

Initial velocity, u = 3m/s

Final velocity, v = 34.5m/s

Time, t = 9 seconds

To find:

Acceleration, a = ?

Formula:

v = u + at

Calculations:

a = (v – u) / t

a = (34.5 – 3) / 9

a = 31.5 / 9

a = 3.5 [tex]m/s^2[/tex]

Result:

The acceleration of the rolling ball is 3.5 [tex]m/s^2[/tex].

Learn more about Acceleration here:

https://brainly.com/question/15366947

#SPJ9

The reactants in a chemical formula is the atoms prior to the chemical reaction, found on the left side of the equation. That is option D.

A chemical formula is defined as the scientific way of representation of chemical compounds either singly or during a chemical reaction.

During a chemical reaction, a chemical formula is made up of a right side and a left side with an arrow at its middle indicating the movement of the energy of the chemical reaction.

The reactants are found located at the left hand side of the chemical formula.

The reactants are made up of elements and compounds which combines to form a new product through the formation of new chemical bonds.

For example in the formation of water,

2H2. + O2. --> 2H2O

Here, Hydrogen and oxygen molecules are the reactants which are seen on the left-hand side of the chemical reaction.

Therefore, The reactants in a chemical formula is the atoms prior to the chemical reaction, found on the left side of the equation.

Learn more about chemical reaction here:

https://brainly.com/question/16416932

#SPJ1

Answer: D

Explanation: I took the quick check

The height of the bridge is 1796.895 m if an object falls from the bridge and strike the water below with a velocity of 187.82 m/sec.

Velocity of the object, v = 187.80 m/s

Height of the bridge will be

According to the three equations of motion,

1) First equation Velocity - Time relation states that,

[tex]v = u + at[/tex]

here 'a' will be the acceleration due to gravity i.e g = 9.8 [tex]\frac{m}{secx^{2} }[/tex]

'v' = 187.80  m/s

'u' = 0 m/s

therefore,

[tex]t = \frac{v - u}{a}[/tex]

[tex]t = \frac{187.80 - 0}{9.81}[/tex]

t = 19.14 sec

2) Second equation Position - Time relation states that,

[tex]s = ut + \frac{1}{2} at^{2}[/tex]

here 'a' will be the acceleration due to gravity i.e g = 9.8 [tex]\frac{m}{secx^{2} }[/tex]

'u' = 0 m/s

't' = 19.14 sec

[tex]s = 0 + \frac{1}{2} 9.81 *(19.14^{2})[/tex]

s = 0 + 4.905 * 366.34

s = 1796.895 m

The height of the the bridge is 1796.895 m.

To know more about three equations of motion here

https://brainly.com/question/14278353

#SPJ1

The Magnitude of the resultant velocity is given by: Vr = squareroot of the addition of (2002 + 502) = 210m/s at 14.04degrees.

The velocity would be roughly 206.16 m/s at a heading of approximately if the airplane were simply following the wind and not attempting to course correct. A compass reading of 14.04 degrees (0 deg being North, 90 deg being East).

Y axis is north, and X axis is east. The line m=rise (y2-y1)/run (x2-x1) = 200/50 has a slope of 4/1. Since a2 + b2 = c2 on the triangle, 40,000 + 2,500 = 42,500. The hypotenuse of our right triangle, which represents the total distance traveled in one second, is equal to 206.16, which is the sq root of that number.

Now, we can determine the heading using TAN = Opposite / Adjacent (the angle x of the line on our graph). TAN (x) = 50/200 = 0.25 so x = 14.04 degrees, approximately.

Learn more about velocity here;

https://brainly.com/question/18084516

#SPJ9

The net force on an object equal to zero When the forces acting on the object are balanced

Option C is correct answer.

Newton's first law states that when the resultant of all forces acting on an object (the net force) is zero, the thing  is in equilibrium. If the thing  is initially at rest, it remains at rest. If it's  initially in motion, it continuously  move with constant velocity.

Learn more about net force of an object :

brainly.com/question/27087547

#SPJ9

During the nuclear change we can expect to see different chemical symbols before and after the change

Chemical and nuclear reactions are quite different from one another. Atoms can share electrons with other atoms or participate in an electron transfer to increase their stability in chemical reactions. In nuclear reactions, the atom's nucleus stabilizes itself by going through some sort of alteration. Compared to the energies involved in chemical reactions, the energies produced in nuclear reactions are many orders of magnitude higher. Environmental factors like temperature or pressure do not significantly affect nuclear reactions like they do with chemical ones.

Nuclear reactions involve a change in an atom's nucleus, usually producing a different element. Chemical reactions, on the other hand, involve only a rearrangement of electrons and do not involve changes in the nuclei

To learn more about Nuclear:

https://brainly.com/question/18187269

#SPJ9

The relation that predicts the velocity, [tex]x(t) = \frac{1}{2} \cdot 4 \cdot {t}^{2} [/tex], gives the velocity at t = 4.5 seconds as 18

The given function for the velocity of the car with time is [tex]x(t) = \frac{1}{2} \cdot 4 \cdot {t}^{2} [/tex]

Comparing the above function with the following equation of motion;

[tex]x(t) = u\cdot t + \frac{1}{2} \cdot a \cdot {t}^{2} [/tex]

We have;

x(t) = The distance traveled after time, t

a = The acceleration = 4

u = The initial velocity = 0

The equation of motion for the velocity as a function of time is; v = u + a•t

Which gives;

v = 0 + 4•t

The velocity of the car at t = 4.5 seconds is therefore;

v = 0 + 4 × 4.5 = 18

The velocity of the car at t = 4.5 is 18

Learn more about the equations of motion here:

https://brainly.com/question/17095161

#SPJ1

app will diagnose a particular disease and suggest the appropriate measures and helps in booking an appointment with the doctor.

Let us assume that self-inventory is a health care application.

It is useful in the domain of health care.

the app will diagnose a particular disease and suggest the appropriate measures and helps in booking an appointment with the doctor.

so this is a computer engineering student's invention he/she can show this in the workplace and can explain them.

this would increase the chances of getting hired.

This also adds to our experience.

For more information on invention click on the link below:

https://brainly.com/question/6463555

#SPJ4

35 is the deceleration

Deceleration is described as a reduction in speed as the body advances away from the beginning position. The opposite of acceleration is deceleration. It is written as. Negative acceleration is another name for deceleration. The formula for calculating acceleration is modified by adding a negative sign to calculate deceleration, which is the exact opposite of acceleration. Deceleration will be since deceleration is determined by dividing the change in velocity by time.

Deceleration is equal to -v/t, where v stands for velocity change and t for time.

Since t = 2 s and v = 70 m/s in this instance,

Deceleration equals -70/2 to -35.

35 mph is the deceleration.

Learn more about deceleration here-

https://brainly.com/question/4403243

#SPJ9

Answer:

D- moves with constant velocity

Explanation:

As we know that acceleration is tge rate of change in velocity.

Since velocity is constant, the change in velocity is zero (∆v=0)

[tex]{ \tt{acceleration = \frac{ \triangle v}{t} }} \\ \\ { \tt{acceleration = \frac{0}{t} }} \\ \\ { \tt{acceleration = 0}}[/tex]

The mass of an atom is its atomic mass. Although the kilogram is the standard international measurement of mass, the unified atomic mass unit, or dalton, is frequently used to express atomic mass. One Da is equal to one-twelfth of a free carbon-12 atom's mass when it is at rest in the ground state.

Which Noble Gas has the lowest average atomic mass?

Ne; Xe; Ar; He

"He - 4.0026Da"

It is written as a multiple of 1.992646547 1023 gram, or one-twelfth of the mass of the carbon-12 atom, which is given an atomic mass of 12 units. In this scale, 1.660539040 1024 gram is equal to 1 atomic mass unit (amu). In honor of English chemist John Dalton, the atomic mass unit is often known as the dalton (Da).

The total mass of the protons, neutrons, and electrons that make up an atom is a little bit less than the observable atomic mass. According to an equation where the energy (E) released equals the product of the mass (m) consumed and the square of the velocity of light in vacuum (c), the difference, known as the mass defect, is accounted for during the combination of these particles by conversion into binding energy; thus, E = mc2.

To know more about Atomic mass, click on the link below:

https://brainly.com/question/15822551

#SPJ9

The balloon hits the ground right before the professor gets there.

The balloon picks up speed due to gravity and we can calculate the time taken for it to fall to the ground as follows:

Gravity (g) = 9.81 m/s²

Height or distance (s) = 11 meters

Initial Speed (u) = 0 m/s

using equation of motion

[tex]s = ut + \frac{1}{2}at^{2}[/tex]

where s = height

u = initial speed

a = acceleration due to gravity

t = time taken

then using above values we get

11 = 0 x 2 + 0.5 x (9.8 x t²)

t = 1.4975

So we can see that the balloon takes 1.4975 seconds to fall to the ground, and since the professor takes 2 seconds to get to that place.

The balloon hits the ground right before the professor gets there.

To know more about equation of motion

https://brainly.com/question/5384119

#SPJ1

When the scientists draw conclusions the scientist find out whether the hypothesis was supported.

A hypothesis is a theory put up to explain a phenomenon. A hypothesis cannot be called a scientific hypothesis unless it can be tested using the scientific process.

Once your experiment is complete, you collect your measurements and analyze them to see if they support your hypothesis.

Scientists frequently discover that their hypotheses and predictions were not supported by the results of their experiments. In these circumstances, they will discuss the results of their experiment before reevaluating their initial theories and predictions in light of the fresh information. The scientific method is essentially restarted in this way. Even if they discover that their theory was correct, they could still wish to verify it once more using a different approach.

The correct option is (a).

Learn more about hypothesis here:

https://brainly.com/question/606806

#SPJ9

With the use of formula, he car's centripetal acceleration is 0.43 m/s²

Angular velocity is the angle turned by a body per time taken. It is measured in radian per second. That is, rad/s

Given that a race car goes around a level, circular track with a diameter of 1.00 km at a constant speed of 75 km/h. What is the car's centripetal acceleration in m/s²

Centripetal Acceleration a = v² / r

Where

Substitute the two parameters into the equation

a = 20.83² / 1000

a = 434.03 / 1000

a = 0.43 m/s²

Therefore, the car's centripetal acceleration is 0.43 m/s²

Learn more about Centripetal Acceleration here: https://brainly.com/question/22103069

#SPJ1

The correct answer is V_f = 1.81 × 10^14.

D = 2cm = 0.02 m

ΔV = 150 V

V_i = 2.6 × 10^5 m/s

The coulomb force,

F = qE

ma = qE

a = qE/m

Potential difference

ΔV = ED

E = ΔV/D

a = qΔV/mD

Using equation of motion,

V_f^2 = V_i^2 + 2ad

V_f = √V_i^2 + 2ad

V_f = √V_i^2 + 2d ( qΔV/mD)

here q= 1.6  × 10^-19 C

m = 9.11 × 10^-31 kg

for d= 0.1 cm =  0.001 m

V_f = √(2.6 × 10^5)^2 + 2 (0.001)(1.6  × 10^-19 C × 150V/9.11 × 10^-31 × 0.02)

V_f = √(6.76 × 10^10) + 0.002(24× 10^-18 C)/1.822× 10^-32)

V_f = √(6.76 × 10^10) + 48 × 10^-15/1.822× 10^-32

V_f = √(6.76 × 10^10) + 26.3 × 10^17

V_f = √33.06 × 10^27

V_f = 1.81 × 10^14

To learn more about Potential difference refer the link:

https://brainly.com/question/23899758

#SPJ9

Answer:

F = 450N

Explanation:

clockwise stock = anticlockwise stock

F(2m) = 600N(1.5m)

2mF/2m = 900Nm/2m

F = 450N

Therefore the magnitude of the effort from the given diagram is 450N.

The element used is of bronze.

Now before we find out how we got the answer as bronze, firstly let us understand about the device we are talking about. That is, spring.

What exactly is a spring?

A spring is defined as a device that changes its shape in response to an external force, returning to its original shape when the force is removed. If we apply force or pressure in this device, it will change its shape but the moment we stop applying force, it will come back to its original state.

This means that this device is made of something flexible. So, the material it is made up of should also be flexible in nature.

How to find out flexibility of spring?

Flexibility of spring can be found as q = f Q, where f is the spring flexibility.

Here, in this question, we are given the mass of element in air and water. This shows a slight comparison between the mass of that particular element in air and water and thus, we get to know it is trying to draw our attention towards density.

Here, we have mass in air and water, thus, we can determine the density.

From these numbers, we can know that the density given is of bronze.

Hence, the element used is Bronze.

To know more spring aggregate, refer : https://brainly.com/question/20215636

#SPJ4

The statement that a teacher sitting in her rolling chair pushes against the wall and moves in the opposite direction exemplifies the third law of motion by Newton.

Newton's third law of motion states that for every action, there is an equal and opposite reaction.

This law describes the nature of a force as the result of a mutual and simultaneous interaction between an object 1 and a second object 2.

According to Newton's third law of motion, whenever two objects A and B interact with each other, they both exert equal but opposite forces upon each other.

Therefore, the statement that a teacher sitting in her rolling chair pushes against the wall and moves in the opposite direction exemplifies the third law of motion by Newton.

Learn more about Newton's law of motion at: https://brainly.com/question/974124

#SPJ1

Answer:

They do exist.

Explanation:

Black holes exist because they could be found almost everywhere maybe there isn't anything inside it but there is many black holes!

Answer: the best evidence is through micro-quasars, also known as x-ray binaries. These objects emit strong x-rays from an Earth-sized region in space.

When the mass of the object decreases the weight of the object will decrease.

Newton's universal law of gravitation states that the force of attraction between any two bodies is inversely proportional to the square of the distance between them and directly proportional to the product of their masses.

We know that weight is the product of applied gravitational force and mass.

Therefore, W = M × G

Where W represents the weight of the object, M is the mass of the object, and G is the gravitational force. As a result, it might also mean that "an object's weight is directly proportionate to its mass."

Therefore, a decrease in mass will result in a decrease in the object's weight.

The correct option is (b).

Learn more about mass here:

https://brainly.com/question/750001

#SPJ9

The complete question is mentioned below:

Which of the following will cause a decrease in an object's weight?

(a) Increase in the mass of the object

(b) Decrease in the mass of the object

(c) Increase in the temperature of the object

(d) Decrease in the temperature of the object