Test 1

A

A 50kg crate is sitting on the table. It has a maximum static friction of 60N (friction to overcome to get moving). If I push on the crate with 50N, what is the crate's acceleration? A) 0m/s2 B) 0.2 m/s2 C) 10m/s2 D) 1.2m/s2 E) 2.2m/s2

E

A 5kg ball is thrown at 10m/s straight upward. Neglecting air resistance, the net fore that acts on the stone when it is halfway to the top of its path is about A) 1/2N B) 1N C) 5N D) 10N E) 50N

D

A boat's motor is producing a velocity of 30mph. The boat is flowing in the same direction as the current of 10mph. What is the velocity of the boat as seen from a person on the shore? A) 10mph B) 20mph C) 30 mph D) 40mph D) 50mph

C

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 bulled C) is the same for each bullet D) depends on how high they started E) none of these

B

A car accelerates at 4 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 80 m/s? A) 2 seconds B) 20 seconds C) 80 second D) 160 seconds

A

A car maintains a constant velocity of 100km/hr for 10 seconds. During this interval its acceleration is A) zero B) 10 k/hr/s C) 110 km/hr/s D) 1000 km/hr/s

A

A car traveling at 100km/hr strikes an unfortunate bug and splatter it. The force of impact is A) the same for both B) greater on the bug C) greater on the car

C

A hamster travels at 2 m/s. How far did it go in 6 seconds? A) 3m B) 6m C) 12m D) 36m E) 72m

B

A marathon runner passes the 5-mile mark at 1 o'clock and the 15-mile mark at 3 o'clock. What is the runner's average speed during this time? A) 2.5 mph B) 5 mph C) 7.5 mph D) 30 mph

C

A person stands on a scale and it reads 800N. What is the person's mass? A) 8kg B) 10kg C) 80kg D) 100kg

C

A person with a weight of 90 N is hanging from three equal vertical ropes. What is the tension in each of these ropes? A) 90N each B) 45 N each C) 30 N each D) 20 N each

D

A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400N of force. What is the tension of the rope? A) zero B) 200N C) 200N D) 400N E) 800N

D

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that A) the milk carton has no acceleration B) there is an action-reaction pair of forces C) gravity tends to hold the milk carton secure D) the milk carton has inertia E) none of these

D

A space ship is being accelerated by its engines until they run out of fuel. When that happens, what happens to the ship? A) It slows down and stops B) It stops abruptly C) It speeds up D) It continues at the speed it had, but no longer acelerates

C

A tow truck exerts a force of 3000N on a car, accelerating it at 2 meters per second per second. What is the mass of the car? A) 500kg B) 1000kg C)1500kg D) 3000kg

B

A truck is slowing down with a constant acceleration(negative). Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor A) exactly below the midpoint of the ceiling B) ahead of the midpoint of the ceiling C) behind the midpoint of the ceiling D) speeds up very quickly E) speeds up very gradually

E

A vehicle with a mass of 40kg on the surface of the Earth is traveling in outer space at a speed of 400m/s. It is stopped by applying a constant force of 20N for A) 20s B) 40s C) 80s D) 400s E) 800s

E

An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the A) combined weight of the arrow and bowstring B) air resistance against the bow C) friction of the ground against the archer's feet D) grip of the archer's hand on the bow E) arrow's push against the bowstring

B

An object falls freely from rest on a planet where the acceleration due to gravity is 3 m/s2. After 5 seconds, the object will have a speed of A) 3m/s B) 15m/s C) 20m/s D) 50m/s E) 60m/s

C

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be A) half as much B) the same C) twice as much D) four times as much

B

An object is pulled northward by a force of 10N and at the same time another force of 15N pulls southward. The magnitude of the net force on the object is A) 0N B) 5N C) 25N D) 150N

E

Basketball players are typically in the air (up and down) for a total of .7s. How high do they jump, assuming no air resistance? A) 7m B) 3.5m C) 2.45m D) 1.25m E) 0.6m

C

During takeoff, an airplane goes from 0 to 50 m/s in 10s. How fast was it going after 6 seconds? A) 6m/s B) 25m/s C) 30m/s D) 50m/s E) 60m/s

A

If an object falls a distance of 2 meters in its first second of fall, then 2 meters in its second second of fall, and 2 meters during its third second of fall, then the acceleration of the falling object is A) 0m/ss B) 2 m/ss C) 4m/ss D) 10m/ss

A

If no external forces are acting on a moving object, it will A) continue moving at the same speed, in a straight line B) continue moving at the same speed, but it can change direction as long as speed doesn't change C) move slower until it finally stops in a straight line D) move slower and slower until it finally stop, but in can change direction

A

If one object has twice as much mass as another object (don't assume same material), it also has twice as much A) inertia B) velocity C) acceleration due to gravity D) volume E) More than one of these

B

If the mass of an object does not change, a constant net force (that's not zero) on the object produces constant A) velocity B) acceleration C) both of these D) neither of these

B

If we do not ignore air resistance in the previous question about the mine shaft, would the mine shaft be deeper or shallower (it still took 6 seconds to fall to the bottom)? A) deeper B) shallower C) air resistance would not change the answer

D

In which direction would the above net force be? A) There is no force B) westward C) northward D) southward

C

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. Ignoring air resistance, how deep is the shaft? A) about 60m B) about 120m C) about 180m D) more than 200m

A

Suppose a probe is being accelerated through space by a 10N force. Suddenly the probe encounters a second force of 10N in the opposite direction from the first force. The probe with both forces acting on it A) continues at the speed it had when it encountered the second force B) is brought to a rapid halt C) decelerates gradually to a halt D) speeds up very quickly E) speeds up very gradually

A

The force required to maintain an object at a constant velocity in free space (no gravity) is equal to A) zero B) the mass of the object C) the weight of the object D) the force required to stop it

B

The maximum acceleration of a car while towing a second car twice its mass, compared to its acceleration with no car in tow, is A) one half B) one third C) one fourth D) the same E) none of these

B

Two balls, 1kg and 10kg, are both in free fall from the top of a crane. The force of gravity on the 10kg ball is? A) zero B) 10 times more than on the 1 kg ball C) The same as on the 1kg ball D) 1/10 times less than the 1kg ball

B

Two people are standing on a frictionless surface, one has a mass of 100kg, and the other has a mass of 50kg. The heavier person hits the lighter person with 100N of force. What is the acceleration of the heavier person? A) zero B) 1m/s2 C) 2m/s2 D) 5m/s2

A

When a cannonball is fired from a cannon, both the cannonball and the cannon experience equal A) amounts of force B) accelerations C) both force and acceleration D) neither

D

When a skydiver of mass 100kg experiences air resistance of 500N, their acceleration is A) about 2 m/s2 B) about 3 m/s2 C) about 4 m/s2 D) about 5 m/s2 E) more than 5 m/s2

C

Which of the following would have the greatest air resistance? A) A ping pong ball B) A bowling ball C) A beach ball

A

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