Kinematics Questions and Answers

In many locations, old abandoned stone quarries have become filled with water once excavating has been completed. While standing on a 10.0-m-high quarry wall, Clarence tosses a piece of granite into the water below. If Clarence throws the rock horizontally with a velocity of 3.0 m/s, how far out from the edge of the cliff will it hit the water?

Pepe, the clown, is jumping on a trampoline as Babette, the tightrope walker, above him suddenly loses her balance and falls off the tightrope straight toward Pepe. Pepe has just started upward at 15 m/s when Babette begins to fall. Pepe catches her in midair after 1.0 s. a) How far has Babette fallen when she is caught by Pepe? b) What is Babette's velocity at the time of contact" c) What is Pepe's velocity at the time of contact? d) How far above the trampoline was Babette before she fell?

A boat traveled 198 miles downstream and back. The trip downstream took 9 hours. The trip back took 99 hours. Find the speed of the boat in still water and the speed of the current. A) boat: 5 mph, current: 16 mph C) boat: 17 mph, current: 14 mph B) boat: 12 mph, current: 10 mph D) boat: 14 mph, current: 14 mph

A mass weighting 56 lbs stretches a spring 3 inches. The mass is in a medium that exerts a viscous resistance of 117 lbs when the mass has a velocity of 6 ft/sec. Suppose the object is displaced an additional 7 inches and released. Find an equation for the object's displacement, u(t), in feet after t seconds. Use the convention: If the displacement is upward then u < 0

One end of a spring is attached to a ceiling. When an object of mass m kilograms is attached to the other end of the spring, the spring stretches to a length of L centimeters as shown in the equation above. What is m when L is 73 ? Un extremo de un muelle está unido a un techo. Cuando un objeto de masa m kilogramos se une al otro extremo del resorte, el resorte se extiende hasta una longitud de L centímetros como se muestra en la ecuación anterior. ¿Qué es m cuando Les 73 ? A) 14 B) 27.7 C) 73 D) 279.5

Kinetic energy equals one-half times the mass of an object times the square of its velocity: KE = (1/2)(m)(v^2). If an object that weighs 5 kilograms has a kinetic energy of 100, what is its velocity? √200 10√/5 2√10 40 200

A 49.0 kg swimmer with an initial speed of 1.28 m/s decides to coast until she comes to rest. Part A If she slows with constant acceleration and stops after coasting 2.00 m, what was the magnitude of the force exerted on her by the water?

Two drivers traveling side-by-side at the same speed suddenly see a deer in the road ahead of them and begin braking. Driver 1 stops by locking up his brakes and screeching to a halt; driver 2 stops by applying her brakes just to the verge of locking, so that the wheels continue to turn until her car comes to a complete stop. Part A All other factors being equal, is the stopping distance of driver 1 greater than, less than, or equal to the stopping distance of driver 2?

What force does a trampoline have to apply to a 45.0-kg gymnast to accelerate her straight up at 7.50 m/s²? Note that the answer is independent of the velocity of the gymnast-she can be moving either up or down, or be stationary.

While hiking Dave stops at a scenic cliff, overlooking a large lake far below. He throws a rock at 25 m/s at an angle of 40 degrees above the horizontal. The rock splashes in the lake, 153 meters from the base of the cliff. (g=9.8 m/s/s) Determine the horizontal component of the initial velocity. Determine the vertical component of the initial velocity.

The tallest volcano in the solar system is the 32 km tall Martian volcano, Olympus Mons. An astronaut drops a ball off the rim of the crater and that the free fall acceleration of the ball remains constant throughout the ball's 32 km fall at a value of 4.3 m/s². (We assume that the crater is as deep as the volcano is tall, which is not usually the case in nature.) Find the time for the ball to reach the crater floor.

A stunt man drives a car off a broken train track and plunges into the valley below. The car was moving at 24 m/s when it went off the track. If the car lands 37 m away from the base of the broken train track, how high was the train track located above the valley?

Rex Things throws his mother's crystal vase vertically upwards with an initial velocity of 26.2 m/s. Determine the height to which the vase will rise above its initial height.

Bob is driving the getaway car after the big bank robbery. He's going 50 m/s when his headlights suddenly reveal a nail strip that the cops have placed across the road 110 m in front of him. If Bob can stop in time, he can throw the car into reverse and escape. But if he crosses the nail strip, all his tires will go flat and he will be caught. Bob's reaction time before he can hit the brakes is 0.6 s, and his car's maximum deceleration is 10 m/s². Part A Does Bob stop before or after the nail strip and by what distance?

A cheetah spots a Thomson's gazelle, its preferred prey, and leaps into action, quickly accelerating to its top speed of 30 m/s, the highest of any land animal. However, a cheetah can maintain this extreme speed for only 15 s before having to let up. The cheetah is 190 m from the gazelle as it reaches top speed, and the gazelle sees the cheetah at just this instant. With negligible reaction time, the gazelle heads directly away from the cheetah, accelerating at 4.6 m/s² for 5.0 s, then running at constant speed. Part A Does the gazelle escape? No, the cheeatah will approach the gazelle during its run at a constant speed. Yes, the gazelle will run more than the cheetah could run at all during the gazelle's acceleration. No, the cheeatah will approach the gazelle during its acceleration. Yes, but in order to escape gazelle needs to maintain the constant speed for a while. By what distance is the gazelle in front when the cheetah gives up? Express your answer with the appropriate units.

A ball is thrown straight upward and rises to a maximum height of 16 m above its launch point. At what height above its launch point has the speed of the ball decreased to one-half of its initial value? 12m

A place kicker kicks a football from 39.6 meters from the goal posts. The kick leaves the ground with a speed of 24.8 m/s at an angle of 49.6 degrees. The goal posts are 3.10-meters high. (Use g=9.8 m/s/s) Determine the horizontal component of the initial velocity. Determine the vertical component of the initial velocity.

A wrecking ball is hanging at rest from a crane when suddenly the cable breaks. The time it takes for the ball to fall halfway to the ground is 1.2 s. Find the time it takes for the ball to fall from rest all the way to the ground.

Which sentence correctly describes a friction force? A. It acts in a direction perpendicular to the motion of an object. B. It acts in the same direction as the motion of an object. C. It acts in a direction opposite to the motion of an object. D. It acts in the same direction as the force of gravity on an object.

A plane that is moving 200 m/s drops a package. The package takes 15 seconds to reach the ground. A) What height was the package dropped from? B) How far did the plane travel from the time the package was released until the package hit the ground? Is this the same distance the package travels? C) How fast was the package moving when it hit the ground?

A ball rolled off a table with an initial velocity of 7.0 m/s. The table is 2.0 m off the ground. a. How long was the ball in the air? b. How far did it travel horizontally? c. How fast was its vertical velocity before it hit the ground?

A 4 g bullet leaves the muzzle of a rifle with a speed of 460.3 m/s. What constant force is exerted on the bullet while it is traveling down the 0.6 m length of the barrel of the rifle? Answer in units of N.

A man jogs at a velocity of 2.5 m/s west for 1,200 s. He then walks at a velocity of 1.0 m/s east for 500 s and then stops to rest. What is the displacement of the man when he stops to rest? A 2,500 m west B. 3,500 m west C. 700 m west D. 3,000 m west

Tom the cat is chasing Jerry the mouse on a table. Jerry puts on the brakes and stops while Tom continues right off the edge of the table at 6.00 m/s. It takes Tom 0.40 seconds to hit the ground. (use g=9.8 m/s/s) The table is approximately how many meters high? How many meters from the tables edge did Tom hit the ground?

A ball at rest is dropped and hits the ground in 1.5 s with a final speed of 15 m/s. How would the acceleration and final speed of the ball be affected if it were dropped from a greater height on Earth? (Ignore friction.) A. Its final speed would remain the same because its rate of acceleration would remain the same. B. Its final speed would increase because its rate of acceleration would remain the same. C. Its final speed would increase because its rate of acceleration would increase. D. Its final speed would remain the same because its rate of acceleration would decrease.

The greatest height reported for a jump into an airbag is 99.4 m by stuntman Dan Koko. In 1948 he jumped from rest from the top of the Vegas World Hotel and Casino. He struck the airbag at a speed of 39 m/s (88 mi/h). To assess the effects of air resistance, determine how fast he would have been traveling on impact had air resistance been absent.

A motorcyclist changes the velocity of his bike from 20.0 meters/second to 35.0 meters/second under a constant acceleration of 4.00 meters/second2. How long does it take the bike to reach the final velocity? A. 2.02 seconds B. -2.02 seconds C. 3.75 seconds D. -3.75 seconds

A toy car runs off the edge of the table that is 1.225 m high. If the car lands 0.400 m from the base of the table: a) How long did it take the car to fall? b) How fast was the car going on the table?

A rocket blasts off from rest at an acceleration of 30 m/s^2. It's fuel and acceleration cut-out after 60 seconds. How high does the rocket go during that time? A. 33 km B. 54 km C. 69 km D. 108 km

A car moving in a straight line increases its speed from 50 km/hr to 65 km/hr in 3 seconds, while a truck goes from rest to 15 km/hr in a straight line during the same time interval. Which undergoes greater acceleration? The car. The truck. Both the same.

A car already traveling at 8 m/s accelerates at 2 m/s² for a total of 15 seconds. How far does the car travel from the start to the end of the acceleration? a. List the correct formula which matches all variables given or implied: b. Show the evaluated version of the formula in this step. c. Simplify the evaluated formula and show the answer for the distance travelled during the acceleration.

An object is launched at a velocity of 20 m/s in a direction making an angle of 25° upward with the horizontal. Draw a free body diagram and diagram showcasing what's happening. a) What is the maximum height reached by the object? b) What is the total flight time (between launch and touching the ground) of the object? c) What is the horizontal range (maximum x above ground) of the object? d) What is the magnitude of the velocity of the object just before it hits the ground?

An airplane moving at 120 m/s accelerates at 8.5 m/s^2 for a total of 30 seconds. If you want to know the distance travelled at the end of those 30 seconds then the most appropriate formula would be: A. Vf = V0 + at B. (Vf)^2 =(VO)^2 + 2ad C. df = d0 +V0t + (1/2) at^2 D. d = ((Vf + V0)/2)t

A duck swims at a constant speed from one side of a river to the other side in a time of 4 seconds. The river is 6 meters wide and it is flowing at a speed of 2 m/s. What is the velocity of the duck and what is its direction of travel, with respect to ground? Draw and diagram to showcase the situation

Onur drops a basketball from a height of 10 m on Mars, where the acceleration due to gravity has a magnitude of 3.7 m/s2 We want to know how many seconds the basketball is in the air before it hits the ground.

Sacks of flour are launched from a horizontal conveyor belt moving at a rate of 2 m/s into bins for packaging. If the surface of the conveyor belt is 1.4 m off the ground, what is the range of each flour sack? Not enough information is given to find the range Undefined ≈ 0.53 m ≈ 1.06 m

At t=0, an object is launched straight up from the ground with an initial velocity of 22 m/s. Ignore air resistance. Part A - What is the speed of the object two seconds after it is launched? Part B - What is the speed of the object three seconds after it is launched?

A small plane is flying at 85 m/s as it passes directly over your brand-new car when a passenger drops his backpack. It takes 9 seconds for the backpack to fall to the ground. You are very worried that the backpack will land on your new car and you wonder if you should move it. What will be the horizontal displacement of the backpack as it fall? Should you move your car?

A basketball player achieves a hang time, the total time of flight, of 0.914 s when dunking the ball. What vertical height will he attain? The acceleration of gravity is 9.8 m/s². Answer in units of m.

A watermelon seed has the following coordinates: x = -3.4 m, y = 1.6 m, and z = 0 m. Find its position vector as (a) a magnitude and (b) an angle relative to the positive direction of the x axis. If the seed is moved to the xyz coordinates (5.2 m, 0 m, 0 m), what is its displacement as (c) a magnitude and (d) an angle relative to the positive direction of the x axis? Put the angles in the range (-180°, 180°].

A stone is thrown straight upward with a speed of 20 m/s. It is caught on its way down at a point 5.0 m above where it was thrown. (a) How fast was it going when it was caught? (b) How long did the trip take?

A motorist traveling at 11 m/s encounters a deer in the road 40 m ahead. If the maximum acceleration the vehicle's brakes are capable of is -5 m/s², what is the maximum reaction time of the motorist that will allow her or him to avoid hitting the deer? Answer in units of s. If his or her reaction time is 2.77636 s, how fast will (s) he be traveling when (s) he reaches the deer? Answer in units of m/s.

Suppose you throw a ball vertically downward with an initial speed of 15 m/s. Neglecting air friction, what would be the speed of the ball one second later? Here, the vertically pointing down acceleration of gravity has the positive sign along with the positive vertically down of the frame of reference, with magnitude g = + 9.8 m/s² A. -9.8 m/s². B. 9.8 m/s². C. 5.2 m/s. D. 15 m/s. E. 24.8 m/s.

A ball rolls of a table with a horizontal velocity of 5 m/s. If it takes 0.6 seconds for it to reach the floor, what is the vertical component of the ball's velocity just before it hits the floor? Here, use the vertically down positive sign for the vertical axis of the frame of reference, with the horizontal axis pointing from left to right. Also, for the vertically down uniform acceleration, use g = + 10 m/s² A. - 5 m/s B. + 5 m/s C. - 6 m/s D. + 6 m/s E. none of the above

A rock thrown with speed 11.0 m/s and launch angle 30.0° (above the horizontal) travels a horizontal distance of d = 16.5 m before hitting the ground. From what height was the rock thrown? Use the value g = 9.800 m/s² for the free-fall acceleration.

If a world-class sprinter ran a distance of 100 meters starting at his top speed of 11 m/s and kept running with constant speed throughout (AKA constant speed), then how long would it take him to cover the 100 m distance? A. 90.9 s B. 9.09 s C. 0.909 D. none of the above.

A toy car is set to run on a straight horizontal track. The toy car starts from the rest and speeds up for 10.0 seconds reaching a speed of 12 m/s. Then it quickly slows down to a stop at a rate of 6.5 m/s². 1. How long is the slowing down period? 2. What is the total distance toy car travelled? To answer above questions: A. Draw a pictorial representation indicating known and unknown parameters and sketch a velocity graph for the motion. B.Then solve either using equations or velocity graph.

A swimmer heads directly across a river swimming at 1.6 m/s relative to still water. She arrives at a point 40 m downstream from the point directly across the river, which is 80 m wide. Determine... a. the speed of the current b. the magnitude of the swimmer's resultant velocity c. the direction of the swimmer's resultant velocity d. the time it takes the swimmer to cross the river

An object is thrown downward with an initial speed of 17 m/s from a height of 76 m above the ground. At the same instant, a second object is propelled vertically up from ground level with a speed of 40 m/s. At what height above the ground will the two objects pass each other? The acceleration of gravity is 9.8 m/s². 2 Answer in units of m.

On a trip to the store around the block a bike rider goes 75 m toward the West and 75 m toward the North at a constant speed of 1.5 m/s. What is the magnitude of the average velocity? 1.6 m/s 1.5 m/s 0.75 m/s 1.1 m/s