Answer:
word for word answers!
Explanation:
1) Part A: By pedaling a bicycle lightly, the rider can go a long way
2) Part B: The two examples mentioned in the video are the handlebars and the brakes
3) Yes, it’s a type of lever because the two pedals rotate around a fixed point
An unknown radioactive sample is observed to decrease in activity by a factor of two in a one hour period. What is its half-life?
Answer:
The half-life is [tex] t_{1/2} = 1.005 h[/tex]
Explanation:
Using the decay equation we have:
[tex]A=A_{0}e^{-\lambda t}[/tex]
Where:
λ is the decay constantA(0) the initial activityA is the activity at time tWe know the activity decrease by a factor of two in a one hour period (t = 1 h), it means that [tex]A = \frac{A_{0}}{2}[/tex]
[tex]\frac{A_{0}}{2}=A_{0}e^{-\lambda*1 h}[/tex]
[tex]0.5=e^{-\lambda*1 h}[/tex]
Taking the natural logarithm on each side we have:
[tex]ln(0.5)=-\lambda[/tex]
[tex]\lambda=0.69 h^{-1}[/tex]
Now, the relationship between the decay constant λ and the half-life t(1/2) is:
[tex]\lambda = \frac{ln(2)}{t_{1/2}}[/tex]
[tex] t_{1/2} = \frac{ln(2)}{\lambda}[/tex]
[tex] t_{1/2} = \frac{ln(2)}{0.69}[/tex]
[tex] t_{1/2} = 1.005 h[/tex]
I hope it helps you!
A 100kg couch is being pushed with 196N of force. As it slides along the ground it experiences a coefficient of friction of 0.1. What is the net force in this situation?
A 300N
B 202N
C 398N
D 98N
Answer:98
Explanation:hope this helps!
A 80 kg parent and a 20 kg child meet at the center of an ice rink. They place their hands together and push. The parent pushes the child with a force of 25 N, what is the force acting on the parent?
Answer:
force acting on the parent = 25 N .
Explanation:
According to third law of Newton , there is equal and opposite reaction to every action . Here force by the parent on child is action and the force by child on parent is reaction . The former is given as 25 N so force by child on parent will also be 25 N .
Answer is 25 N .
which energy resource is renewable
A. oil
B. natural gas
C. moving water
D. Fossil fuel
Answer:
It's C. Moving Waterrrr
The change in motion (acceleration) of an object depends on
The size of the force
The mass of the object
BOTH the size of the force AND the mass of the object
Answer:
BOTH the size of the force AND the mass of the object
Explanation:
Acceleration of an object is the rate of change of its velocity.
The relation between force, mass and acceleration is given by the formula as follows :
F = ma
m is mass
a is acceleration
It would mean that the change in motion or the acceleration of an object depends on both the size of the force and the mass of the object. Hence, the correct option is (c).
A 500 kg car is moving at 30 m/s. The driver sees a barrier ahead. If the car takes 100 m to come to rest, what is the magnitude of the force necessary to stop the car?
How do you solve this question?
Answer:
F = 2250 [N]
Explanation:
In order to solve this problem, we must first use the following equation of kinematics.
[tex]v_{f}^{2} =v_{o}^{2}-2*a*x[/tex]
where:
Vf = final velocity = 0 (come to rest)
Vo = initial velocity = 30 [m/s]
a = acceleration or desaceleration [m/s²]
x = distance = 100 [m]
[tex](0)=30^{2} -2*a*100\\900 = 200*a\\a = 4.5 [m/s^{2}][/tex]
Now we must use the following equation of kinetics, which is based on Newton's second law that explains that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
F = force [N]
m = mass = 500 [kg]
a = acceleration = 4.5 [m/s²]
[tex]F = 500*4.5\\F = 2250 [N][/tex]
A. A piece of paper near a magnet
B. An aluminum nail near a magnet
C. An iron nail, not near a magnet
D. An iron nail near a magnet
Answer:
it’s c not d
Explanation:
took the test
Answer: D!!!
Explanation: jus got it wrong from the other answer.
The scientific term describing the ball changing position as it goes from
Steph Curry's hand, into the air, and through the hoop.
A= velocity
B= speed
C= vector
D= motion
Answer:
Vector
Explanation:
Vector is a quantity that shows the direction or path through which a body travels with as it changes position.
As body travels, the direction sometimes changes and this is described by the vector of the body.
Velocity is a vector quantity that describes the displacement per unit of time of a body.
Speed is a scalar that deals with the distance covered per time
So, a vector specifies the magnitude of a physical quantity and also the direction through which it travels.
A statement of the second law of thermodynamics is that:__________.
a) spontaneous reactions are always exothermic.
b) energy is conserved in a chemical reaction that has a decrease in entropy.
c) spontaneous reactions are always endothermic.
d) in a spontaneous process, the entropy of the universe increases.
Answer:
in a spontaneous process, the entropy of the universe increases.
Explanation:
Entropy is a measure of of the degree of randomness or disorderliness in a system.
The second law of thermodynamics can be stated as follows; "in any spontaneous process, the entropy of the universe increases."
The universe here refers to the system's disorder and the disorder of the surroundings. Therefore, a spontaneous process can occur, in which the entropy of the system decreases, only if the entropy increases in the surroundings.
For instance, when ice freezes, the entropy of liquid water decreases, that is, the entropy of the system decreases. However, heat is given off to the surroundings and the entropy of the surroundings increases. This is an obvious expression of this law.
Your electric drill rotates initially at 5.21 rad/s. You slide the speed control and cause the drill to undergo constant angular acceleration of 0.311 rad/s2 for 4.13 s. What is the drill's angular displacement during that time interval?
Answer:
The drill's angular displacement during that time interval is 24.17 rad.
Explanation:
Given;
initial angular velocity of the electric drill, [tex]\omega _i[/tex] = 5.21 rad/s
angular acceleration of the electric drill, α = 0.311 rad/s²
time of motion of the electric drill, t = 4.13 s
The angular displacement of the electric drill at the given time interval is calculated as;
[tex]\theta = \omega _i t \ + \ \frac{1}{2}\alpha t^2\\\\\theta = (5.21 \ \times \ 4.13) \ + \ \frac{1}{2}(0.311)(4.13)^2\\\\\theta = (21.5173 ) \ + \ (2.6524)\\\\\theta =24.17 \ rad[/tex]
Therefore, the drill's angular displacement during that time interval is 24.17 rad.
Which change in an object would increase the force needed to move the object?
А.
decreasing the velocity of an object
B
increasing the volume of an object
с
decreasing the mass of an object
D
increasing the mass of an object
Answer:
D i think
Explanation:
Heavier objects (objects with more mass) are more difficult to move and stop.
Answer:
Increasing the mass of the object (option D in the list of answers)
Explanation:
Recall that F = m x a
therefore, if the mass increases, the force increases
3) A 10kg object rests on a frictionless surface when it is struck by a 300N force. At what rate will it accelerate?
3m/s/s
30m/s/s
0.3m/s/s
300m/s/s
Answer: 0.3m/s/s
(i'm really sorry if i'm wrong)
:(
A 20 kg wagon is rolling to the right across a floor. A person attempts to catch and stop the crate and applies a force of 70 N, 180.0 on it. If the coefficient of friction is 0.18, calculate the deceleration rate of the wagon as it is caught.
Answer:
1.736m/s²
Explanation:
According to Newton's second law;
[tex]\sum F_x = ma_x\\[/tex]
[tex]Fm - Ff = ma_x\\[/tex] where;
Fm is the moving force = 70.0N
Ff is the frictional force acting on the body
[tex]Ff = \mu R\\Ff = \mu mg\\[/tex]
[tex]\mu[/tex] is the coefficient of friction
m is the mass of the object
g is the acceleration due to gravity
a is the acceleration/deceleration
The equation becomes;
[tex]Fm - Ff = ma_x\\Fm - \mu mg = ma\\[/tex]
Substitute the given parameters
[tex]Fm - \mu mg = ma\\70 - 0.18(20)(9.8) = 20a\\70-35.28 = 20a\\34.72 = 20a\\a = \frac{34.72}{20}\\a = 1.736m/s^2\\[/tex]
Hence the deceleration rate of the wagon as it is caught is 1.736m/s²
As a bicycle is ridden west in a straight line with decreasing speed,the acceleration of the bicycle must be
Answer:
Decreasing
Hope this helps! :)
Thorium^+2
Chemical symbol:
Atomic Number:
Mass: 232
# of protons
# of neutrons
Group #
Period #
Answer:
chemical symbol: Th
atomic number:90
protrons :90
neutrons:142
group#:4
period#: 9
Explanation:
you take the atomic weight (232.038)and subtract the atomic number to get (90) which is your neutrons
d. If a dog has a mass of 12 kg, what is its weight on Neptune?
11.7N/kg
Answer:
133.8 N
Explanation:
Recall that the acceleration of gravity in Neptune is estimated as 11.15 m/s^2
Therefore, the weight of the dog on this planet would be:
Weight = mass x acceleration of gravity = 12 kg x 11.15 m/s^2 = 133.8 N
What is the algebraic sign (+ or -) for designating the distance and velocity vectors for an object in free fall?
Answer:
positive- downward
negative- upward
Explanation:
A vector is a quantity described by a magnitude and a direction.
The algebraic sign, positive (+) and negative (-) are used to designate the distance and velocity vectors for an object in free fall where positive represents downward and negative represents an upward movement of the object.
Hence, the correct answer is "positive- downward and negative- upward".
A 60-kg jogger runs up a long flight of
stairs in 4.0 s. The vertical height of the
stairs is 4.5 m.
a. Estimate the jogger's power
output in watts and horsepower.
b. How much energy did this
require?
Explanation:
Given parameters:
Mass of Jogger = 60kg
Time = 4s
Vertical height = 4.5m
Unknown:
Jogger's power output = ?
Energy required = ?
Solution:
The power output of the jogger is defined as the rate at which work is done.
Power = [tex]\frac{force x distance}{time}[/tex]
Now insert the parameters and solve;
Work done = Force x distance = mgh
m is the mass
g is the acceleration due to gravity = 9.8m/s²
h is the height
Work done = 60 x 9.8 x 4.5 = 2646J
Power = [tex]\frac{2646}{4}[/tex] = 661.5W
Energy required;
The work done here is also the energy required;
Energy required = 2646J
The energy required is 2646 J and the jogger's power output 661.5 W.
Given here,
Mass of Jogger = 60 kg
Time = 4s
Vertical height = 4.5 m
The power output of the jogger is defined as the rate of energy tranfer work is done.
Power = W/t
Where,
W- work = mgh = 60 kg x 9.8 m/s² x 4.5 m = 2646 J
t - time - 4 s
Put the values, we get
Power = 661.5W
To know more about power,
https://brainly.com/question/8288959
on the moon which object would fall with the same acceleration?
Answer:
Since there is no air resistance on the Moon, all objects would be in free fall at 1.6 m/s2. This means that they would all hit the ground at the same time if released simultaneously from the same height, but at a slower speed compared to objects free falling in a vacuum on Earth.
Explanation:
What is the minimum angular velocity (in rpm) for swinging a bucket of water in a vertical circle without spilling any? The distance from the handle to the bottom of the bucket is 35 cm.
Complete Question
What is the minimum angular velocity (in rpm) for swinging a bucket of water in a vertical circle without spilling any? The distance from the handle to the bottom of the bucket is 35 cm. The student has 70-cm-long arms
Answer:
The value is [tex]w__{rpm} } = 29.17 \ rpm[/tex]
Explanation:
From the question we are told
The distance from the handle to the bottom of the bucket is [tex]d = 35 \ cm = 0.35 \ m[/tex]
The length of the students arm is L = 70 cm = 0.70 m
Generally the acceleration due to gravity experienced by the bucket of water is mathematically represented as
[tex]g = w^2 * r[/tex]
Here is is the radius of the circle which swinging of the bucket makes and this is mathematically represented as
[tex]r = L + d[/tex]
So
[tex]g = w^2 * ( L + d )[/tex]
= > [tex]w = \sqrt{\frac{g }{ L + d } }[/tex]
= > [tex]w = \sqrt{\frac{ 9.8}{ 0.7 + 0.35} }[/tex]
= > [tex]w = 3.055 \ rad/s[/tex]
Generally the angular speed in revolution per minute is mathematically represented as
[tex]w__{rpm} } = \frac{w * 60 }{2 \pi }[/tex]
=> [tex]w__{rpm} } = \frac{3.055 * 60 }{2 * 3.142 }[/tex]
=> [tex]w__{rpm} } = 29.17 \ rpm[/tex]
which of the following to all food chains depend on in an ecosystem
Answer:
The sun is the ultimate source of energy for all food chains. Through the process of photosynthesis, plants use light energy from the sun to make food energy. Energy flows, or is transferred through the system as one organism consumes another.
A hare can run at a rate of 15 m/s, while a turbocharged tortoise can now crawl at a rate of 3 m/s, how much of a head-start (time-wise) does the tortoise need in order to tie the hare in a 250 meter race?
A.
16.7 seconds
B.
66.7 seconds
C.
83.3 seconds
D.
100 seconds
Answer:
t = 66.7 s
Explanation:
Given that,
Speed of a hare, v = 15 m/s
Speed of a turbocharged tortoise, v' = 3 m/s
The hare in a 250 meter race
Let the Hare takes time t. It can be calculated as follows :
[tex]t=\dfrac{250}{15}=16.67\ s[/tex]
Let a turbocharged tortoise takes t'. It can be calulated as follows :
[tex]t'=\dfrac{250}{3}= 83.33\ s[/tex]
To tie the race, required time is given by :
[tex]\Delta t = t'-t\\\\=83.33-16.67\\\\=66.66\ s\\\\\approx 66.7\ s[/tex]
Hence, the correct option is (b) i.e. 66.7 seconds.
One of the harmonics of a column of air in a tube that is open at both ends has a frequency of 448 Hz, and the next higher harmonic has a frequency of 576 Hz. What is the fundamental frequency of the air column in this tube?
Answer:
The fundamental frequency is [tex]f_1 =128 \ Hz[/tex]
Explanation:
From the question we are told that
The frequency of one harmonics is [tex]f_x= 448 \ Hz[/tex]
The next higher harmonic is [tex]f_z = 576 \ Hz[/tex]
Generally the frequency of an air column open at both ends is mathematically represented as
[tex]f_n = \frac{nv }{ 2 L }[/tex]
Here n is the order of the harmonics (frequency)
v is the velocity of the sound
L is the length of the column
So for one harmonics we have that
[tex]f_k = \frac{n v }{2L}[/tex]
Then for the next higher harmonics
[tex]f_x = \frac{n+1 ) v}{2 L }[/tex]
Generally the difference between these frequencies is mathematically represented as
[tex]f_z- f_x = \frac{(n+1 )v}{ 2L} - \frac{(n )v}{ 2L}[/tex]
=> [tex]576 - 448 = \frac{vn + v - nv }{2L}[/tex]
=> [tex]\frac{ v }{2L} = 128[/tex]
Generally for fundamental frequency n = 1
So
[tex]f_1 = n * \frac{v}{2L}[/tex]
So
[tex]f_1 =1 * 128[/tex]
=> [tex]f_1 =128 \ Hz[/tex]
. A horizontal steel spring has a spring constant of 40.0 N/m. What force must be applied to the spring in order to compress it by 10.0 cm?
Ans 4 more to be exact
Explanation:
Given values are:
Spring constant,
k = 40 N/mand,
x = 10 mThe force will be:
→ [tex]F = kx[/tex]
By substituting the values, we get
[tex]= 40\times 10[/tex]
[tex]= 400 \ N[/tex]
Thus the above answer is right.
Learn more about spring constant here:
https://brainly.com/question/15277652
A ball is thrown off a cliff at a speed of 10 m/s in a horizontally direction. The ball reaches the ground 1.5 seconds. If the ball is launched a second time at the same speed from a second higher cliff, which of the following is true?
A. The ball takes a longer time and lands further away from the foot of the cliff.
B. The ball takes longer to hit the ground, but lands at the same distance from the foot of the cliff.
C. The ball takes the same time lands at the same distance from the foot of the cliff.
D. The ball falls further away from the foot of the cliff, but takes the same time.
What would its weight be on Jupiter?
24.9N
Answer:
1.898 × 10^27 kg
Explanation:
thats how much it ways
Under state law, what is the blood-alcohol limit for legally operating a motor vehicle?
Answer:
HOPE IT HELPS.....
Explanation:
The legal standard for drunkenness across the United States ranges from 0.10 to 0.08. If a person's BAC measures 0.08, it means that there are 0.08 grams (i.e., 80 mg) of alcohol per 100 ml of blood. The American Medical Association says that a person can become impaired when the blood alcohol level hits 0.05.
Answer: 0.08
Driving While Intoxicated or Impaired is Illegal
Under Michigan law, it is illegal to drive: While intoxicated, or impaired, by alcohol, controlled substance, or other intoxicating substance. With a bodily alcohol content of 0.08 or more. (This crime is one of the driving while intoxicated offenses.)
Hope this helps... Stay safe and have a Merry Christmas!!!!!!!! :D
n
Question 4
1 pts
A bus travels on an interstate highway at an average speed of 90 km/hrs. How far does it take to travel
in 30 mins? The distance equals speed times time, or d = st.
O 45 km
O 98 Km
O 56 km
O 432 Km
[tex]d = s \times t \\ d = 90 \times \frac{30}{60} \\ d = 90 \times \frac{1}{2 } \\ d = 45km[/tex]
Forces of 70 N at 130 degrees, and 20 N at an angle of 280 degrees, measured counter-clockwise from the positive x-axis, act on an object.
A. What are the components (F1x, F1y) of the first force force (in Newtons)?
B. What are the components (F2x, F2y) of the second force force (in Newtons)?
C. What are the components (Fx, Fy) of the resultant force (in Newtons)?
D. What is the magnitude of the resultant force (in Newtons)?
E. What is the angle of the resultant force with respect to x-axis?
Answer:
A. ) F₁ₓ = -45.0 N F₁y = 53.6 N
B.) F₂ₓ = 3.48 N F₂y = -19.7 N
C.) Fₓ = -41.5 N Fy = 33.9 N
D) F = 53.6 N
E) θ = -39. 2º (320.8º)
Explanation:
A)
Applying simple trig, like definitions of cos and sin of an angle, we can get the x- and y- components of F₁, as follows:[tex]F_{x1} = F_{1} * cos (130) = 70 N * cos (130) = -45 N (1)\\F_{y1} = F_{1} * sin (130) = 70 N * sin (130) = 53.6 N (2)[/tex]
B)
Repeating for F₂:[tex]F_{x2} = F_{2} * cos (280) = 20 N * cos (280) = 3.48 N (3)\\F_{y2} = F_{2} * sin (280) = 20 N * sin (280) = -19.7 N (4)[/tex]
C)
The x- and y- components of the resultant force, are just the algebraicsum of the x- and - y components of F₁ and F₂:
Fₓ = Fₓ₁ + Fₓ₂ = -45 N + 3.48 N = -41.5 N (5)By the same token, Fy can be written as follows:Fy = Fy₁ + Fy₂ = 53.6 N + (-19.7 N) = 33.9 N (6)D)
The magnitude of the resultant force can be obtained applying the Pythagorean Theorem to Fx and Fy, as follows:[tex]F_{t} =\sqrt{F_{x} ^{2} + F_{y} ^{2} } = \sqrt{(-41.5N)^{2} +(33.9N)^{2}} = 53.6 N (7)[/tex]
E)
Finally the angle regarding the x- axis of the resultant force vector, can be obtained using the definition of the tangent of an angle, as follows:[tex]\theta = arc tg \frac{33.9N}{(-41.5N)} = arc tg (-0.817) = -39. 2 \deg[/tex]
A diffraction grating with 68 slits per cm is used to measure the wavelengths emitted by hydrogen gas.
A. At what angles in the fourth-order spectrum would you expect to find the two violet lines of wavelength 434 nm and of wavelength 410 nm?
B. What are the angles if the grating has 12,800 slits per cm?
Answer:
a
[tex]\theta _1 =0.687 ^o[/tex]
[tex]\theta _2 =0.630 ^o[/tex]
b
Generally given that the domain arcsine function is between -1 and 1 then the arcsine of 2.22 will not be valid
Generally given that the domain arcsine function is between -1 and 1 then the arcsine of 2.1 will not be valid
Explanation:
From the question we are told that
The slit grating is [tex]N = 68 \ slits / cm = 6800 \ slits / m[/tex]
The order of spectrum is [tex]n = 4[/tex]
Generally the width of the slit is mathematically represented as
[tex]a = \frac{1}{ 6800}[/tex]
=> [tex]a = 0.000147 \ m[/tex]
Generally the condition for constructive interference is
[tex]asin\theta = n * \lambda[/tex]
Now for the first wavelength the angle is evaluated as
[tex]\theta _1 = sin ^{-1} [ \frac{n \lambda_1 }{a} ][/tex]
=> [tex]\theta _1 = sin ^{-1} [ \frac{4* 434 *10^{-9} }{ 0.000147 } ][/tex]
=> [tex]\theta _1 =0.687 ^o[/tex]
Now for the second wavelength the angle is evaluated as
[tex]\theta _2 = sin ^{-1} [ \frac{n \lambda_2 }{a} ][/tex]
=> [tex]\theta _2 = sin ^{-1} [ \frac{4* 410 *10^{-9} }{ 0.000147 } ][/tex]
=> [tex]\theta _2 =0.630 ^o[/tex]
Gnerally if grating is [tex]N = 12800 \ slits per cm = 1280000 \ slits / m[/tex]
Generally the width of the slit is mathematically represented as
[tex]a = \frac{1}{ 1280000}[/tex]
=> [tex]a = 7.813 *10^{-7} \ m[/tex]
Generally the condition for constructive interference is
[tex]asin\theta = n * \lambda[/tex]
Now for the first wavelength the angle is evaluated as
[tex]\theta _1 = sin ^{-1} [ \frac{n \lambda_1 }{a} ][/tex]
[tex]\theta _1 = sin ^{-1} [ \frac{4* 434 *10^{-9} }{ 7.813*10^{-7} } ][/tex]
=> [tex]\theta _1 = sin ^{-1} [ 2.22][/tex]
Generally given that the domain arcsine function is between -1 and 1 then the arcsine of 2.22 will not be valid
=> [tex]\theta _1 =0.687 ^o[/tex]
Now for the second wavelength the angle is evaluated as
[tex]\theta _2 = sin ^{-1} [ \frac{n \lambda_2 }{a} ][/tex]
=> [tex]\theta _2 = sin ^{-1} [ \frac{4* 410 *10^{-9} }{ 7.813*10^{-7} } ][/tex]
=> [tex]\theta _2 = sin ^{-1} [2.1 ][/tex]
Generally given that the domain arcsine function is between -1 and 1 then the arcsine of 2.22 will not be valid