Conceptual physics
At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately A) 40m/s B) 50m/s C) 55m/s D) 60m/s
Answer: A - 40m/s
A car accelerates at 2 meters per second. Assuming the car starts s from rest, how much time does it need to accelerate to a speed of 30m/s A) 2 seconds B) 15 seconds C) 30 seconds D) 60 seconds E) none of these
Answer: B - 15 seconds
If a car increases its velocity from zero to 60 m/s in 10 seconds, its acceleration is A) 3km/h/s B) 6km/h/s C) 10km/h/s D) 60km/h/s E) 600km/h/s
Answer: B - 6km/h/s
A ball is thrown 125 meters upward and then falls the same distance back to earth. Neglecting air resistance, its total time in the air is A) about 5 seconds B) about 10 seconds C) about 15 seconds D) more than 20 seconds
Answer: B - about 10 seconds
If an object moves with constant acceleration, its velocity must A) be constant also B) change by the same amount each second C) change by varying amounts depending on its speed D) always decrease
Answer: B - change by the same amount each second
Drop a rock from a 5-m height and it accelerates at 10 m/s2 and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is about A) half as much B) the same amount C) twice as much D) four times as much
Answer: B - the same amount
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? A) about 60m B) about 120m C) about 180m D) more than 200m
Answer: C - about 180m
Disregarding air resistance, objects fall with constant A) velocity B) speed C) acceleration D) distances each successive second
Answer: C - acceleration
The two measurements necessary for calculating average speed are A) acceleration and time B) velocity and time C) distance and time D) distance and acceleration E) velocity and distance
Answer: C - distance/time
Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed will be A) then one thrown upward B) the one thrown downward C) neither - - they will both hit with the same speed
Answer: C - neither - - they will both hit with the same speed
A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s? A) 2m B) 10m C) 40m D) 100m E) 200m
Answer: D - 100m
A man leans over the edge of a cliff and throws a rock upward at 4.9m/s. Neglecting air resistance, two seconds later the rock's speed is A) zero B) 4.9m/s C) 9.8m/s D) 14.7m/s E) none of the above
Answer: D - 14.7m/s
A car accelerates from rest for 5 seconds until it reaches a speed of 20 m/s. What is the car's acceleration in meters per second per second? A) 1 B) 2 C) 3 D) 4 E) 5
Answer: D - 4
At one instant an object in free fall is moving downward at 50 m/s. One second later its speed should be about A) 25m/s B) 50m/s C) 55m/s D) 60m/s E) 100m/s
Answer: D - 60m/s
If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about A) 2m/s B) 3m/s C) 4m/s D) 6m/s
Answer: D - 6m/s
An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 seconds, the object will have a speed of A) 5m/s B) 10m/s C) 20m/s D) 50m/s E) 100m/s
Answer: E - 100m/s
If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be A) constant B) less and less each second C) greater than the second before D) doubled
Answer: C - greater than the second before
A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second A) is less than 9.8 B) is 9.8 C) is more than 9.8 D) depends on the height of the cliff
Answer: C - is more than 9.8
The muzzle velocity of a bullet fired from a new rifle is. 100m/s. Neglecting air resistance, at the end of one second a bullet fired straight up into the air will have traveled a distance of A) (100-4.9)m B) (100+4.9)m C) 100m D) 4.9m E) none of these
Answer: A - (100-4.9)m
An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration is A) 0 B) 5 C) 8 D) 24
Answer: A - 0
A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is A) about 30m/s B) about 60m/s C) about 120m/s D) more than 120m/s
Answer: A - about 30m/s
A ball is thrown upwards and returns to the same position. Compared with its original speed after release, its speed when it returns is about A) half as much B) the same C) twice as much D) four times as much
Answer: B - the same
Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to the level from which you tossed it? A) 5m/s B) 7.5m/s C) 10m/s D) 15m/s E) 20m/s
Answer: C - 10m/s
Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration? A) 0.25 B) 2.8 C) 4.0 D) 10 E) 40
Answer: C - 4.0
If a projectile is fired straight up at a speed of 10m/s, the time it takes to reach the top of its path is about A) 1 second B) 2 seconds C) 10 seconds D) not enough information to estimate
Answer: A - 1 second
A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds? A) about 50m/s B) about 60m/s C) about 80m/s D) about 100m/s E) about 110m/s
Answer: A - about 50m/s
While an object near the Earth's surface is in free fall, its A) velocity increases B) acceleration increases C) mass increases D) mass decreases
Answer: A - velocity increases
A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is A) zero B) 10km/hr C) 110km/hr D) 1000km/hr
Answer: A - zero
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is A) zero B) equal to its weight C) equal to its weight divided by its mass D) equal to the product of its mass times its weight
Answer: A - zero
An apple falls from a tree and hits the ground 5 meters below. It hits the ground with a speed of about A) 5m/s B) 10m/s C) 15m/s D) 20m/s E) not enough information given to estimate
Answer: B - 10m/s
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about A) 5m/s B) 10m/s C) 15m/s D) a variable amount E) depends on its initial speed
Answer: B - 10m/s
If a projectile is fired straight up at a speed of 10m/s, the total time to return to its starting position is about A) 1 second B) 2 seconds C) 10 seconds D) 20 seconds E) not enough information to estimate
Answer: B - 2 seconds
An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the earth, its speed one second later would be A) 10m/s B) 20m/s C) 30m/s D) 40m/s
Answer: B - 20m/s
If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20m/s/s, then its speed reading would increase each second by A) 10m/s B) 20m/s C) 30m/s D) 40m/s E) depends on its initial speed
Answer: B - 20m/s
A man leans over the edge of a cliff and throws a rock upward at 4.9m/s. Neglecting air resistance, one second later the rock's speed is A) zero B) 4.9m/s C) 9.8m/s D) 14.7m/s E) none of the above
Answer: B - 4.9m/s
If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be A) less than a 9.8 meter per second per second B) 9.8 meters per second per second C) greater than 9.8 meters per second per second
Answer: B - 9.8 meters per second per second
A man leans over the edge of a cliff and throws a rock upward at 4.9m/s. How far below the level from which it was thrown is the rock 2 seconds later? A) 4.9m B) 9.8m C) 14.7m D) 19.6m
Answer: B - 9.8m
Consider drops of water that leak at a steady rate from a dripping faucet. As the drops fall they A) get closer together B) get farther apart C) remain at a relatively fixed distance from one another
Answer: B - get farther apart
A ball is thrown upwards and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is always A) more than the speed it had when thrown upwards B) less than the speed it had when thrown upwards C) the same as the speed it had when thrown upwards D) impossible to determine
Answer: B - less than the speed it had when thrown upwards
When a rock thrown straight upwards gets to the exact top of its path, its A) velocity is zero and its acceleration is zero B) velocity is zero and its acceleration is about 10 meters per second per second C) velocity is about 10 m/s and its acceleration is zero D) velocity is about 10m/s and its acceleration is about 10 meters per second per second E) none of these
Answer: B - velocity is zero and its acceleration is about 10 meters per second per second
An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as on Earth. In the first 5 seconds it falls a distance of A) 100m B) 150m C) 250m D) 500m E) none of the above
Answer: C - 250m
If a rocket initially at rest accelerates at a rate of 50 m/s2 for one minute, its speed will be A) 50m/s B) 500m/s C) 3000m/s D) 3600m/s
Answer: C - 3600m/s
One half second after starting from rest, a freely falling object will have a speed of about A) 20m/s B) 10m/s C) 5m/s D) 2.5m/s E) none of the above
Answer: C - 5m/s Diff: 2 Topic: linear motion
The vertical height attained by a basketball player who achieves a hang time of a full 1 s is A) about 0.8m B) about 1m C) about 1.2m D) about 2.5m E) more than 2.5m
Answer: C - about 1.2m
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? A) about 60m B) about 120m C) about 180m D) more than 200m
Answer: C - about 180m
A bullet is dropped from the top of the Empire State Building while another bullet is fired downward from the same location. Neglecting air resistance, the acceleration of A) the fired bullet is greater B) the dropped bullet is greater C) each bullet is 9.8 meters per second per second
Answer: C - each bullet is 9.8 meters per second per second
A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water A) is greater for the dropped bullet B) is greater for the fired bullet C) is the same for each bullet D) depends on how high they started E) none of these
Answer: C - is the same for each bullet
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always A) in the direction of motion B) opposite its velocity D) directed upward E) directed downward
Answer: D - directed downward
In each second of fall, the distance a freely falling object will fall is A) about 5m B) about 10m C) the same, but not 5m or 10m D) increasing E) none of these
Answer: D - increasing
In each second of fall, the distance a freely falling object will fall is A) about 5m B) about 10m C) the same, but not 5m or 10m D) increasing E) none of these
Answer: D - increasing
Twelve seconds after starting from rest, an object falling freely will have a speed of A) 10m/s B) 50m/s C) 100m/s D) more than 100m/s
Answer: D - more than 100m/s
Starting from rest, the distance a freely falling object will fall in 0.5 seconds is about A) 1m B) 10m C) 1.00m D) none of the above
Answer: D - none of the above
While a car travels around a circular track at a constant speed, its A) acceleration is zero B) velocity is zero C) inertia is zero D) none of the above
Answer: D - none of the above
