Kinematics Questions and Answers

Pedro and Joanna decide to try a problem. A baseball is thrown from the top of a tall building with an initial velocity of 13.5 m/s from a height of h = 11 m above the ground. Find its speed when it reaches the ground if its launch angle is -14°. Find its speed if it is launched horizontally.

A 52.0-kg projectile is fired at an angle of 30.0° above the horizontal with an initial speed of 128 m/s from the top of a cliff 126 m above level ground, where the ground is taken to be y = 0. (a) What is the initial total mechanical energy of the projectile? (Give your answer to at least three significant figures.) (b) Suppose the projectile is traveling 90.7 m/s at its maximum height of y= 297 m. How much work has been done on the projectile by air friction? (c) What is the speed of the projectile immediately before it hits the ground if air friction does one and a half times as much work on the projectile when it is going down as it did when it was going up?

A cyclist is travelling with a speed of 12.0 m/s when she applies the brakes. After slowing for 3.0 s, her speed has been reduced to 4.0 m/s. (a) What distance does she travel during this time? (b) What is her acceleration? (c) If she continues braking, how much longer will it take her to stop? (d) If she continues to travel with her new speed, how far will she travel during the next 3.0 s?

Sometimes you have to do the problem in two steps: A car moving at 28 m/s comes to a stop in 14 s. Find the distance it covers. Here we see that vo = 28 m/s, v=0 m/s (comes to a stop), and t = 14 s, and they want x. We don't have a formula that relates vo, v, t and x. So: • first use v = Vo + at to find a • then use x = Vot + 1/2 at² to find x

If the displacement of velocity is given by a = 2-v (k is a positive constant) then velocity of the particle as a function of time t will be (given its position is zero at t=0)

A particle moves along x-axis according to the equation x = t³ – 9t² + 24t + 3, then Particle moves in positive direction in interval 3 < t < 5 The particle reverses direction of motion two times during it motion In interval 2 st≤ 4 sec average acceleration of particle is zero Distance travelled by particle in interval 0 ≤ t ≤ 2 is 20 m

For a particle moving along x-axis, velocity is given as a function of time as v = 2t² + sin t. At t=0 particle is at origin =, Find the position as a function of time?

A car approaches a red stop light at 5 m/s. The light turns green as the car reaches the traffic light. So the car accelerates at +2 m/s². Assuming the acceleration is constant and that the road is straight, how far (in meters) from the traffic light will the car go in 5 s? 150 m 70 m 100 m 25 m 50 m

A 65 kg sprinter, starting from rest, runs 40 m in 7.0 s at constant acceleration. What is the magnitude of the horizontal force acting on the sprinter? What is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s?

You run to campus to make it on time for your Physics 2 class. The lecture hall is 1 mile from your dorms. You run at the speed of 4 miles per hour to your class. The class lasts 1.5 hours. After, you go straight back to your dorm. However, you are tired so you walk with a speed of 2 miles per hour. What is your average speed at the time interval you left the dorms and you came back. 1 miles/hour 0 miles/hour 0.9 miles/hour 3 miles/hour 1.7 miles/hour

A jogger is running at +4.0 m/s when a bus passes her. The bus accelerates from +16.0 m/s to +20.0 m/s in 8.0 s. The jogger speeds up with the same acceleration of the bus over 16.0 s. What is the jogger's new velocity? A. +8.0 m/s B. +12.0 m/s C. +16.0 m/s. D. +20.0 m/s E. +24.0 m/s

A ball rolling down a hill was displaced 21.9 m while uniformly accelerating from rest. If the final velocity was 7.14 m/s, what was the rate of acceleration? Blank 1: 1.16

One strategy in a snowball fight is to throw -a snowball at a high angle over level ground. While your opponent is watching this first snowball, you throw a second snowball at a low angle and time it to arrive at the same time as the first. Assume both snowballs are thrown with the same initial speed 14.6 m/s. The first snowball is thrown at an angle of 50° above the horizontal. At what angle should you throw the second snowball to make it hit the same point as the first? Note the starting and ending heights are the same. The acceleration of gravity is 9.8 m/s².

In a local bar, a customer slides an empty beer mug down the counter for a refill. The height of the counter is 1.26 m. The mug slides off the counter and strikes the floor 1.00 m from the base of the counter. (a) With what velocity did the mug leave the counter? m/s (b) What was the direction of the mug's velocity just before it hit the floor? (below the horizontal)

A toy rocket launcher can project a toy rocket at a speed as high as 32.0 m/s. (a) If air resistance can be ignored, how high (in m) would a toy rocket launched at this speed rise if projected straight up? m (b) How long would the toy rocket be in the air (in s)? S

Salmon often jump waterfalls to reach their breeding grounds. Starting downstream, 3.14 m away from a waterfall 0.517 m in height, at what minimum speed must a salmon jumping at an angle of 27.6° leave the water to continue upstream? The acceleration due to gravity is 9.81 m/s². Answer in units of m/s. A ball is thrown horizontally from the top of a building 87 m high. The ball strikes the ground 66 m horizontally from the point of release. What is the speed of the ball just before it strikes the ground?

Stephanie serves a volleyball from a height of 0.80 m and gives it an initial velocity of +7.6 m/s straight up. How high will the volleyball go? The accel- eration of gravity is 9.81 m/s². Answer in units of m. How long will it take the ball to reach its maximum height? Answer in units of s.

A knight sits on a castle wall during a siege. To while away the time, he notes that boul- ders catapulted from below land on the top of his wall with a vertical velocity of 5.4 m/s. If he is 30 m above the catapult, what is the initial velocity of the boulders? The acceleration of gravity is 9.8 m/s². Answer in units of m/s.

A car starts from rest and accelerates for 3.4 s with an acceleration of 3.3 m/s². How far does it travel? Answer in units of m. Your answer must be within 3.0% Answer in units of m Your answer must be within ±3%.

An astronaut drops a feather from 2 m above the surface of the moon. If the acceleration of gravity on the moon is 1.69 m/s2, how long does it take the feather to reach the surface? Answer in units of s

An automobile traveling along a straight road increases its speed from 44 ft/s to 63 ft/s in 180 ft. If the acceleration is constant, how much time elapses while the auto moves the 180 ft? Answer in units of s.

At 1:00 p.m. a car, traveling at a constant velocity of 98 km/h toward the west, is 24 km to the west of our school. How far from the school will it be at 3:30 p.m.? Answer in units of km.

A block is moving along the x-axis and its position varies in time according to the expression x = (3.00 m/s²)t2, where x is in meters and t is in seconds. (a) Determine its position (in m) at t = 2.10 s. (b) Determine its position (in m) at t = (2.10 s) + Δt. (Use the following as necessary: Δt. Do not include units in your answer.) (c) Evaluate the limit of as Δt approaches zero to find the velocity (in m/s) at t = 2.10 s.

The upper half of an inclined plane of inclination is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by μ =2/ tanθ μ = 2tanθ μ= tanθ μ=1/tanθ

A conveyor belt is moving at a constant speed of 2m/s, a box is gently dropped on it. The coefficient of friction between them is 0.5. The distance that the box will move relative to belt before coming to rest on it (taking g = 10ms-² ), is: A 1.2m B 0.6m C zero D 0.4m

Standing on the edge of a tall cliff, a curious man drops a rock, m₁, and 1.00 s later, throws a second rock, m₂, downwards with a speed of 19.6 m/s. The mass of the second rock, m₂, is twice the mass of m₁. Assume no friction from air. Determine the acceleration of the center of mass of the system 4 seconds later. Give your answer to two significant figures.

2. A girl leaves a history classroom and walks 10. meters north to a drinking fountain. Then she turns and walks 30. meters south to an art classroom. What is the girl's total displacement from the history classroom to the art classroom? A) 20. m south C) 40. m south B) 20. m north D) 40. m north

A car starts from rest and reaches a final linear speed of 45 mi/hr in 3 seconds, what is the linear acceleration of the car? Given: Find: Formula: Reformulation:

A monkey of mass 15kg is climbing on arope with one end fixed to the ceiling. If it wishes to go up with an acceleration of 1m/s how much force should it apply to the rope ? If the rope is 5m long and the monkey starts from rest, how much time will it take to reach the cieling?

Sally travels by car from one city to another. She drives for 30.0 min at 80.0 km/h, 12.0 min at 105 km/h, and 45.0 min at 40.0 km/h, and she spends 15.0 min eating lunch and buying gas. a. Determine the average speed for the trip. b. Determine the total distance traveled.

An aircraft is flying at a height of 3400 m above the ground. If the angle subtended at a ground observation point by the aircraft positions 10.0 s apart is 30°, what is the speed of the aircraft?

A trip is taken that passes through the following points in order Point A Om Point B 15.0m Point C -30.0 m Point D 20.0 m Point E -10.0 m Point F 5.0 m What is the displacement from Point B to Point F? 90m right 90m left. 10.0 m left 10.0 m right

6. Sandra pulls from the front while Shirley pushes a wagon with Heather riding with a net force of 50-N. The wagon has a combined mass with Heather riding of 30 kg. a) What is the acceleration of the wagon. b) If starting from rest, how much speed will the wagon pick up if they move it for 5 seconds. c) What distance does the wagon cover in 10s. *

Two balls of equal volume and masses m₁ andm₂ (m₂ > m₁) connected with a thin light thread are dropped from a certain height, Viscous drag of air on a ball depends by the ball. When the balls acquire a uniform velocity after a sufficient time from instant they were dropped, what is the tensile force in the thread? Acceleration due to gravity is g. A zero B (m₂ - m₁)g C 0.5(m2 + m1)g D 0.5(m2m₁)g

2.19 An antelope moving with constant acceleration covers the distance between two points 70.0 m apart in 6.00 s. Its speed as it passes the second point is 15.0 m/s. What are (a) its speed at the first point and (b) its acceleration?

A car having an initial velocity of 12 meters per second east slows uniformly to 2 meters per second east in 4.0 seconds. The acceleration of the car during this 4.0-second interval is A) 2.5 m/s² west C) 6.0 m/s² west B) 2.5 m/s² east D) 6.0 m/s2 east

5.) A nice old man invites you and your friends to evaluate his new amusement park. While enjoying one of the attractions, the power goes out! Meanwhile, the water in your drinking cup starts to vibrate... A short time later, an angry Tyrannosaurus Rex is running straight towards your parked jeep. A T-Rex can run at 45 mph (20.11 m/s), and this one is already at full speed, a distance of 150 m away. a. If you do nothing, how long will it take the T-Rex to reach your jeep? b. Cleary, you must go faster. You hit the gas the moment you see the T-Rex. What acceleration a would the jeep need in order to match the T-Rex's speed in exactly 6 seconds? C. Let's assume the jeep accelerates from rest at 2.3 m/s² to get away. After 8s, how far apart are the jeep and the dinosaur? 8:56 PM

12. A rock is thrown downward from the top of a cliff with an initial speed of 12 m/s. If the rock hits the ground after 2.0 s, what is the height of the cliff? (Disregard air resistance. a = g = -9.81 m/s².)

The fastest recorded pitch in Major League Baseball was thrown by Nolan Ryan in 1974. If this pitch were thrown horizontally, the ball would fall 0.809 m (2.65 ft) by the time it reached home plate, 18.3 m (60 ft) away. The acceleration of gravity is 9.81 m/s². How fast was Ryan's pitch? Answer in units of m/s.

2.21 . A Fast Pitch. The fastest measured pitched baseball left the pitcher's hand at a speed of 45.0 m/s. If the pitcher was in contact with the ball over a distance of 1.50 m and produced con- stant acceleration, (a) what acceleration did he give the ball, and (b) how much time did it take him to pitch it?

When a ball of mass m is dropped from rest from a height h, its kinetic energy just before landing is K. Now, suppose a second ball of mass 4m is dropped from rest from a height h/4. Choose the best explanation from among the following: The reduced drop height results in a reduced kinetic energy. The two balls have the same initial energy. The more massive ball will have the greater kinetic energy.

While playing Quidditch, Katie passes the quaffle straight down to Alicia. If Katie throws the ball at the speed to 4 m/s, how fast will the ball be going when Alicia catches it half a second later?

A steel cable lying flat on the floor drags a 20 kg block across a horizontal, frictionless floor. A 110 N force applied to the cable causes the block to reach a speed of 4.1 m/s in a distance of 2.0 m. Part A What is the mass of the cable? Express your answer with the appropriate units.

A 3.30 g coin is placed 15.0 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of H=0.870 and 0.450. Part A What is the maximum angular velocity with which the turntable can spin without the coin sliding?

When Maggie applies the brakes of her car, the car slows uniformly from 15.0 m/s to 0.0 m/s in 2.50 s. How many meters before a stop sign must she apply her brakes in order to stop at the sign?

Mr. Fernandez rolls an 8kg bowling ball on a table (why? Because he-wanted to, that's why). The table is 1.00 meter off the ground and the ball landed 3.00 meters away from the table. How fast did he roll the ball? Is Fernandez stronk?

In a relay race, runner A is carrying the baton and has a speed of 3.40 m/s. When he is 25.0 m behind the starting line, runner B starts from rest and accelerates at 0.140 m/s². How long afterwards will A catch up with B to pass the baton to B? 5.17 S 20.4 s 11.9 s 9.03 s Runner A never catches up.

How long is the ball in the air before it hits the ground? (The student moves her hand out of the way.) Express your answer with the appropriate units.

Quoting directly from Our Place in Space: Other handy numbers for the solar system: • Jupiter is about 300 times the mass of the Earth • The Sun is 1000 times the mass of Jupiter • The radius of Jupiter is about 11 times the radius of Earth, but 1/10th the radius of the Sun. In the last two decades, thousands of exoplanets have been discovered (planets that orbit other stars). Although a lot of speculation is written about many of these planets, because they are so difficult to observe, typically only a very few characteristics can be learned about these distant worlds. Direct measurements of the masses and radii are possible, but not much else! Consider the planet SWEEPS-11 b which has been measured to have a mass of 9.7 x the mass of Jupiter and a radius of 1.13 x the radius of Jupiter. How many Earth masses is equivalent to the mass of planet SWEEPS-11 b? Earth masses

A cyclist maintains a constant velocity of 5.8 m/s headed away from point A. At some initial time, the cyclist is 243 m from point A. What will be his displacement from his starting position after 41 s? Answer in units of m.