.A hard rubber ball, released at chest height, falls to the pavement and bounces back to nearly the same height. When it is in contact with the pavement, the lower side of the ball is temporarily flattened. Suppose the maxi-mum depth of the dent is on the order of 1 cm. Find the order of magnitude of the maximum acceleration of the ball while it is in contact with the pavement. State your assumptions, the quantities you estimate, and the values you estimate for them.
Answer:
a = 1.1 10⁵ m / s²
Explanation:
This is a momentum exercise, where we use the relationship between momentum and momentum
I = ∫ F dt = Δp
= p_f - p₀
as they indicate that the ball bounces at the same height, we can assume that the moment when it reaches the ground is equal to the moment when it bounces, but in the opposite direction
F t = 2 (m v)
therefore the average force is
F = 2 m v / t
where in general the mass of the ball unknown, the velocity of the ball can be calculated using the conservation of energy
starting point. Done the ball is released with zero initial velocity
Em₀ = U = mgh
final point. Upon reaching the ground, just before the deformation begins
Em_f = K = ½ m v²
energy is conserved in this system
Em₀ = Em_f
m g h = ½ m v²
v = √ (2gh)
This is the velocity of the body when it reaches the ground, so the force remains
F = 2m √(2gh) /t
where the height of the person's chest is known and the time that the impact with the floor lasts must be estimated in general is of the order of milli seconds
knowing this force let's use Newton's second law
F = m a
a = F / m
a = 2 √(2gh) / t
We can estimate the order of magnitude of this acceleration, assuming the person's chest height of h = 1.5 m and a collision time of t = 1 10⁻³ s
a = 2 √ (2 9.8 1.5) / 10⁻³
a = 1.1 10⁵ m / s²
r = (2+2+1) i - (t+1)] + t3 k
what is the direction of initial velocity
Answer:
In the - j direction, that is negative of the y-axis
Explanation:
As typed in the question, the position of the object is given by the expression in three component ( i, j, k) form:
r (t) = 5 i - (t + 1 ) j + t^3 k
and since the velocity is the derivative of position with respect to time, by doing the derivative of this expression we get:
v(t) = 0 i - 1 j +3 t^2 k
which for the initial velocity requested (that is at time zero) we have:
v(t) = 0 i - 1 j +3 (0)^2 k = = 1 j
Then the direction of the initial velocity is entirely in the direction of the j versor, that is pointing to the negative of the y-axis.
What potential difference is required to produce a current of 0.5 A in a bulb of power 60 W
Answer:
ans is 120
Explanation:
I= 0.5 A
p= 60w
p=Iv
60/0.5
v= 120
Answer:
V=P/I
V=60/0.5
V=120
Explanaton:
the formula P=IV is converted to V=P/I to make V (voltage) the subject. then sub in the values to get your answer
note that potential difference is same as voltage
Which is not one of the basic nutrients of your body?
1.Vitamins
2.Minerals
3.Molecules
4.Protein
True or false: points that lie on the same plane are Collinear
A car slowed down from 70 mils to 30 mi/s on the highway in 20
seconds. What was the car's acceleration?
A box measures 3.12 ft in length, 0.0455 yd in width and 7.87 inches in height. Since volume can be found using length x width x height, find the volume in cubic centimeters. Now find the volume in gallons.
Explanation:
This problem is on units conversion
given the dimensions
3.12 ft in length,
0.0455 yd in width and
7.87 inches in height
we have to convert to cm first
3.12 ft to cm=
1 ft-------30.48cm
3.12--------x
x=95.09cm
0.0455 yd to cm
0.0455yd ft to cm=
1 yd-------91.44cm
0.0455--------x
x=4.16cm
7.87 in to cm
1 in-------2.54cm
7.87--------x
x=19.98cm
the volume is =95.09cm*4.16cm*19.98cm
volume= 7907.45cm^3
the volume in gallon is
1 cm^3------0.000264172gal
7907.45cm^3-------x
x=7907.45*0.000264172
x=2.088gallons
The position of a particle is r⃗ (t)=(3.0t2iˆ+5.0jˆ−6.0tkˆ)m. (a) Determine its velocity and acceleration as functions of time. (b) What are its velocity and acceleration at time t = 0?
Explanation:
It is given that,
The position of a particle is given by :
[tex]r(t)=(3t^2i+5j-6tk)\ m[/tex]
(a) Velocity of a particle is given by :
[tex]v=\dfrac{dr(t)}{dt}[/tex]
Putting values,
[tex]v=\dfrac{d}{dt}(3t^2+5-6t)\\\\v=(6ti-6k)\ m/s[/tex]
The acceleration of the particle is given by :
[tex]a=\dfrac{dv}{dt}\\\\a=\dfrac{d}{dt}(6t-6)\\\\a=6i\ m/s^2[/tex]
(b) At t = 0,
Velocity, v = 6k m/s
Acceleration, a = 6i m/s²
A ball rolls off a 1.0 m high table and lands on the floor 3.0 m away from the table. a. How long is the ball in the air?
Answer:
The ball is in the air for approximately 0.45 seconds
Explanation:
We only need to use the information on the height of the table to find the time, since the vertical movement is a movement under the acceleration of gravity, and with no initial velocity in the y-direction (recall that the ball rolls off a 1.0 m high table)
therefore the equation of motion for the vertical component is:
[tex]y_f-y_i=\frac{1}{2}\, g\,t^2[/tex]
which for our information becomes:
[tex]y_f-y_i=\frac{1}{2}\, g\,t^2\\1 = 4.9\,t^2\\t^2=\frac{1}{4.9} \\t=\sqrt{\frac{1}{4.9}} \\t\approx 0.45\,s[/tex]
A penny is dropped from the top of the chrysler building ( 320 m high) . How fast is it moving when it hits the ground?
A place kicker launches a kickoff at an angle of 25° to the horizontal and at a velocity of 20 m/s. Calculate the initial velocities in the x- and y-directions.
On a still water, a speedboat decreases its speed uniformly from 30 m/s to 20 m/s. How long does it take the boat to travel a distance of 200m?
a. -8 s
b. 8 s
c. -200 s
d. 200 s
Answer:
t=8
Explanation:
u have solution I give solution also
don't mark plzz follow y
When students were surveyed about the kind of thinking they considered to be most important in their academic studies, the majority chose?
Answer:Critical Thinking
Explanation:
7.2 in college success text back
blutions math practice
Maddie Hicks: Attempt 1
07.5 ml
Question 4 (1 point)
You have a stock bottle of 3mM tetrodotoxin solution, but your protocol states that
you need 6ml of 1mM tetrodotoxin (MW=319.27 g/mol). How much of your 3mM
stock solution (liquid) should you use to make the 1mM solution?
Answer:
[tex]V_1=2mL[/tex]
Explanation:
Hello,
In this case, considering this as a dilution problem, the first step here is to consider that the moles of tetrodotoxin remains the same and just the volumes and concentrations are modified from the initial stock (1) and the required dilution (2):
[tex]V_1M_1=V_2M_2[/tex]
Whereas V is referred to volume and M to molar concentration, in this case in mM. In such a way, solving the V1 as the volume of the 3-mM solution we obtain:
[tex]V_1=\frac{V_2M_2}{M_1} \\\\V_1=\frac{6mL*1mM}{3mM} \\\\V_1=2mL[/tex]
It means you need 2 mL of the 3-mM solution.
Best regards.
Which is the process by which a solid changes to a liquid? O condensation O evaporation O melting sublimation
Answer:
Melting
Explanation:
The process in which a solid changes to a liquid is called melting. This process is also termed as fusion. Due to application of heat and pressure, the internal energy of a solid increases and the molecules become far from each other due to which it starts to melt.
Hence, the correct option is (c) "melting".
Answer:
c. melting
Explanation:
took the quiz on edge
during which stage do you have sleepwalking and sleeptalking
A. stage 2
B. stage 4
C. REM
D. stage 1
In order to have good physical fitness, you __________. A. should be able to complete daily tasks without being physically taxed B. must be able to run a 4-minute mile C. need to work out at the gym four times a week D. don't need to worry about eating healthy foods
Answer:
A) should be able to complete daily tasks without being physically taxed
Explanation:
B) you dont need to run that fast to have good physical fitness
C) you dont need to workout four times a week
D) you should always eat healthy as diet contributes to health
In order to have good physical fitness, you should be able to complete daily tasks without being physically taxed.
What is physical fitness?Physical fitness is the ability to be fit to do work without getting tired easily.
Exercise and workouts are necessary to build and improve physical fitness.
Exercises required include jogging and running.
Therefore, in order to have good physical fitness, you should be able to complete daily tasks without being physically taxed.
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A car runs around a circular race track from the point A to diametrically opposite point B The radius of the circle is ‘r’ . The distance traveled by the car is ________ the displacement of the car is _________ show your work!
Answer:
Distance = πr
Displacement = 2r
Explanation:
First we need to find the distance covered by the car. As the car is travelling on a circular path and it traveled to a diametrically opposite point on the circular path. Therefore, the distance covered by the car must be the half value of the circumference.
Distance = Circumference/2
Distance = 2πr/2
Distance = πr
Since, displacement is the straight line distance between two points. So, the displacement in moving from a point to its diametrically opposite point must be equal to the diameter of circle:
Displacement = Diameter
Displacement = 2r
Does the US use the metric system? Please Only Real Answers Like Yes Or No Or yes because...... no because...... Thank You
Answer:
No
Explanation: It is the only country that does not. Hope this helped :)
Ricardo finds an online site about the gas laws. The site shows the equation below for Charles’s law. What change would correct the error on the site? “Charles’s law” should read “Gay-Lussac’s law,” which explains changes in volume and temperature. The symbol for T2 should be smaller than for T1 because if volume increases, then temperature should decrease. Each T should be replaced by a P in the equation because Charles’s law describes changes in volume and pressure. The volume should be divided by temperature on each side of the equation.
Answer:
D. The volume should be divided by temperature on each side of the equation.
Explanation:
Charles's Law is [tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex].
Answer:
The volume should be divided by temperature on each side of the equation.
Explanation:
Torque can be best described as which of the following? Give an example of both a force and a torque and explain why in a couple of sentences.
A. Rotational force.
B. Rotational velocity.
C. Rotational energy.
D. Rotational power.
E. All of the above.
Answer: rotational force
Explanation:
Torque is the twisting force which cause rotation and the axis of rotation is the point at which the object rotates.
Torque is a rotational force as it leads to the rotation of an object about an axis. Force simply means a pull or push. When an unbalanced ball acts on a force, the ball, the ball will be moved towards the linear motion.
Then, the unbalanced force that is acting in the ball produces torque which causes the ball's rotational motion.
The Torque is best described as a rotational force.
It is the force that causes an object to rotate. Torque is measured in Newton-meters (N-m).
An example of a force is the force of gravity. When you hold a ball in your hand, the force of gravity is pulling down on the ball.
However, the ball is not rotating because the force of gravity is being counteracted by the force of your hand pushing up on the ball.
An example of a torque is when you use a wrench to loosen a bolt. When you apply force to the wrench, you are creating a torque that is trying to turn the bolt.
The more force you apply, the greater the torque.
Torque is not the same as rotational velocity. Rotational velocity is the rate at which an object is rotating. It is measured in radians per second (rad/s).
Torque is also not the same as rotational energy.
Rotational energy is the energy that an object has due to its rotation.
It is measured in joules (J).
Torque is also not the same as rotational power. Rotational power is the rate at which rotational energy is transferred. It is measured in watts (W).
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Which value represents accuracy: the mean, median, mode, range from center, or distance between farthest beanbags?
Answer:
the mean
Explanation:
The mean (informally, the “average“) is found by adding all of the numbers together and dividing by the number of items in the set: 10 + 10 + 20 + 40 + 70 / 5 = 30. The median is found by ordering the set from lowest to highest and finding the exact middle. The median is just the middle number: 20.
why Newtown made the laws of motion
Answer:Newton’s law also states that larger bodies with heavier masses exert more gravitational pull, which is why those who walked on the much smaller moon experienced a sense of weightlessness, as it had a smaller gravitational pull. To help explain his theories of gravity and motion, Newton helped create a new, specialized form of mathematics.
Explanation:
Answer:
Newton was convinced the planets must obey the same physical laws that are observed on Earth. This meant there must be an unseen force acting on them. He knew from experiment that, in the absence of an applied force, a moving body will continue in a straight line forever.
Explanation:
What is 902 in proper scientific notation?
What is the term for heat transfer because of the movement of electromagnetic waves?
What is the ultimate source of energy for an ecosystem?
Answer:
Obviously the answer is Sun...
A girl delivering newspapers covers her route by traveling 6.00 blocks west, 3.00 blocks north, and then 7.00 blocks east. HINT (a) What is her final position relative to her starting location? (Enter the magnitude in blocks and the direction in degrees north of east.) magnitude blocks direction ° north of east (b) What is the length (in blocks) of the path she walked?
Answer:
a) we can form a triangle in order to use the Pythagorean theorem = 3² + 1² = h²
h² = 9 + 1 = 10
h = √10
h = 3.1623 blocks
we must also find the angle at the initial point of the triangle (A):
tan⁻¹ (1/3) = 18.43°
the position relative to her starting position is 90° - 18.43° = 71.57° north of east
b) total distance traveled = 6 + 3 + 7 = 16 blocks
Select the correct answer. As per the new modified method of classifying the magnitude of stars, what kind of values were the brightest stars assigned? A. negative values B. positive values C. fractional values D. letters
Answer:
A. Negative values
Explanation:
Answer:
A-negative values
Explanation:
As per the new modified method of classifying the magnitude of stars, what kind of values were the brightest stars assigned?
A.
negative values
B.
positive values
C.
fractional values
D.
letters
Lizard: A lizard is running in a straight line according to the following: xx(tt) = tt3⁄3 − tt2 + tt He starts at tt = 0. (a) Determine vv(tt). (b) When is the lizard at rest? (c) When is the lizard moving in the positive xx direction? (d) When is the lizard moving in the negative xx direction? (e) When does the lizard have zero acceleration?
Answer:
Explanation:
a ) x ( t ) = t³ / 3 - t² + t
v = dx / dt = 3 t² / 3 - 2 t + 1 = t² - 2 t + 1
b ) lizard is at rest , v( t ) = 0
t² - 2 t + 1 = 0
( t - 1 )² = 0
t = 1
c )
velocity is positive when
t² - 2 t + 1 > 0
( t - 1 ) ² > 0
Here we see that LHS is a square so it is always positive whatever be the value of t
So velocity is always positive or lizard is always moving in positive x direction .
d ) It never moves in negative x direction .
e )
a ( t ) = dv / dt = 2t - 2
t = 1
so it has zero acceleration at t = 0 .
If a 65-kilogram astronaut exerts a force with a magnitude of
50. N on a satellite that she is repairing, the magnitude of the
force that the satellite exerts on her is
50N.
The magnitude of the reaction to any force is equal to the magnitude of the first force. (See Newton #3.)
The satellite will also apply the same magnitude of force ( 50 N ) but in opposite direction.
Given data:
The mass of astronaut is, m = 65 kg.
The magnitude of force exerted on the satellite is, F = 50 N.
In this problem, we will apply the Newton's Third Law of motion, which says that, "To every action, there is an equal and opposite reaction". Which means if any object (say object 1) apply some force on another object (say object 2), then the object 2 will also apply same magnitude of force on object 1, but it will be in opposite direction.
In the given problem, the satellite will also apply the same magnitude of force on Astronaut.
Which means,
F' = - F
F' = - 50 N.
Negative sign shows that the direction of force is opposite.
Thus, we can conclude that the satellite will also apply the same magnitude of force ( 50 N ) but in opposite direction.
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