Physics Test 1

B

A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across the horizontal surface and comes to a rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about a) 10 N b) 50 N c) 5 N d) 25 N e) none of these

C

A 1000 kg car and a 2000 kg car are hoisted the same distance. Raising the more massive car requires a) more than four times as much work b) as much work c) twice as much work d) four times a much work e) less work

B

A 2kg mass has 40 J of potential energy with respect to the ground. Approximately how high is it above the ground? a) 1 m b) 2 m c) 3 m d) 4 m e) None of these

D

A 5 kg shark swimming at a speed of 1 m/s swallows an absent minded 1 kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is a) 2/3 m/s b) 3/2 m/s c) 1/2 m/s d) 1/6 m/s e) 1/5 m/s

C

A 5000 kg freight car runs into a 10,000 kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What is the initial speed of the 5000 kg car? a) 4 m/s b) 5 m/s c) 6 m/s d) 8 m/s e) None of these

E

A TV set is pushed a distance of 2 m with a force of 20 N. How much work is done on the set? a) 2 J b) 10 J c) 800 J d) 20 J e) 40 J

B

A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s? a) 2 seconds b) 15 seconds c) 30 seconds d) 60 seconds e) None of these

A

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is a) 0 b) 1000 km/hr c) 10 km/hr d) 110 km/hr

C

A car that travels twice as fast as another when braking to a stop will skid a) The same distance. b) Twice as far. c) Four times as far.

A

A car that travels twice as fast as another when braking to a stop will skid a) four times as far b) twice as far c) depends on the mass of the cars

B

A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is a) greater on the car b) the same for both c) greater on the bug

B

A coconut and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is a) the same on each b) greater on the coconut c) greater on the feather

C

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is a) 800 N b) 200 N c) 400 N d) none of theses e) 1600 N

D

A rifle recoils while firing a bullet. The speed of the rifle's recoil is small because a) momentum is mainly concentrated in the bullet b) force against the rifle is smaller than against the bullet c) momentum of the rifle is small d) rifle has much more mass than the bullet

B

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is a) between 0 and -10 b) -10 c) less than -10 d) 0

E

A scientific statement that can never be changed a) principle b) hypothesis c) law d) theory e) none of these

C

A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second. What is the mass of the car? a) 500 kg b) 1000 kg c) 1500 kg d) 3000 kg e) None of these

C

A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second. What is the mass of the car? a) 500 kg b) none of these c) 1500 kg d) 1000 kg e) 3000 kg

C

A well tested hypothesis that describes a phenomena is called a a) educated guess b) prediction c) law d) theory

D

According to Newton's law of inertia, a rail road train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains a) are much too heavy b) move too slowly c) must go up and down hill d) always have forces that oppose their motion

D

According to Newton's law of inertia, a rail road train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains a) move too slowly. b) are much too heavy. c) must go up and down hills d) always have forces that oppose their motion

B

An apple falls from a tree and hits the ground 5 meters below. it hits the ground with a speed of about a) 5 m/s b) 10 m/s c) 20 m/s d) 15 m/s e) not enough information given to estimate

A

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 in meters per second per second is a) 0 b) 24 c) 5 d) 8

E

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) 5 m/s. b) 10 m/s. c) 20 m/s. d) 50 m/s. e) 100 m/s.

B

An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The magnitude of the resultant force on the object is a) 25 N b) 5 N c) 0 N d) 150 N

A

At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed in meters per second is approximately a) 40 m/s b) 50 m/s c) 60 m/s d) 55 m/s

D

Drop a rock from a 5 m height and it accelerates at 10 m/s/s 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) four times as much b) twice as much c) half as much d) the same amount

A

During a single orbit the ISS travels 40,000 km in 5000 seconds. What is the average velocity during this orbit? a) 0 km/s b) .125 km/s c) 8 km/s d) 200000000 km/s

B

Forces are equal and opposite here. Which are not always equal and opposite? a) Impulses b) Accelerations c) Momentum changes d) All are equal and opposite

A

If a car increases its velocity from 60 km/h in 10 seconds, its acceleration is a) 6 km/h/s b) 10 km/h/s c) 60 km/h/s d) 3 km/h/s e) 600 km/h/s

D

If an object moves with constant acceleration, its velocity must a) be constant also b) change by varying amounts depending on its speed c) always decrease d) change by the same amount each second

C

If no external forces are acting on a moving object it will a) continue moving at the same speed b) move slower and slower until it finally stops c) continue moving at the same velocity

C

If your automobiles runs out of fuel while you are driving the engine stops but you do not come to an abrupt stop. The concept that most explains why is a) acceleration b) gravity c) inertia d) resistance

C

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? a) 60 m b) 120 m c) 180 m d) More than 200 m

A

Joe pushes Bill, who is asleep. Bill a) pushes Joe equally hard even without waking up b) pushes Joe immediately, but not as hard c) does not push even after he wakes up d) will inevitably push Joe when he wakes

E

Maintain a 1 N force on an ocean liner and its max speed will be a) 0 m/s b) 1 m/s c) <1 m/s d) ~10 m/s e) Almost the speed of light

A

Padded dashboards in cars are safer in an accident than non-padded ones because an occupant hitting the dash has a) Increased time of impact. b) Decreased time of impact. c) Decreased impulse. d) Increased momentum.

A

Science is a body of knowledge that a) all of these choices are correct b) is an ongoing activity of humans c) none of these choices are correct d) condenses knowledge into testable laws e) describes order in nature

A

Strange as it may seem, it is just as hard to accelerate a car on a level surface on the moon as it is here on the Earth. This is because a) the mass of the car is independent of gravity. b) the weight of the car is independent of gravity. c) Nonsense! A car is much more easily accelerated on the moon than on the Earth.

C

Suppose you and a pair of life preservers are floating down a swift river. You wish to get to either of the life preservers. One is 3 meters upstream, the other 3 meters downstream. Which can you swim to in the shortest time? a) The preserver upstream b) The preserver downstream c) Both require the same time

C

The Earth pulls on the moon. Similarly the moon pulls on the Earth a) The earth's pull is larger b) The moon's pull is larger c) Both the earth and the moon pull with the same force

C

The difference between impulse and impact force involves the a) distance the force acts b) mass and its effect on resisting a change in momentum c) time the force acts d) difference between acceleration and velocity

B

The force of friction on a sliding object is 10 newtons. The applied force needed to maintain a constant velocity is a) less than 10 N b) 10 N c) more than 10 N

A

The force required to maintain an object at a constant velocity in free space is equal to a) Zero b) The mass of the object c) The weight of the object d) The force required to stop it e) None of these

B

Twelve seconds after starting from the rest, an object falling freely will have the speed of a) 100 m/s b) more than 100 m/s c) 10 m/s d) 50 m/s

D

What task requires the most work; lifting a 50-kg sack 2 meters or lifting a 25-kg sack 4 meters a) the 25-kg sack b) impossible to determine without knowing the contents of the sack c) the 50-kg sack d) both require the same amount of work

C

When a rocket ship accelerating in outer space runs out of fuel it a) accelerates for a short time, then slows down to a constant velocity. b) accelerates for a short time, slows down, and eventually stops. c) no longer accelerates.

B

When bullets are fired from an airplane in the forward direction, the momentum of the airplane will be a) increased b) decreased c) unchanged

A

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. In this way the average force your body experiences is a) about 1/10 as great b) about 10 times as great c) less than 1/10 as great d) more than 1/10 as great

C

Which of the following is not a vector quantity? a) velocity b) all are vector quantities c) speed d) acceleration

C

Which would be more damaging? a) Drive into a wall. b) Head on collision, same mass, same speed. c) They are equivalent.

C

While a car travels around a circular track at a constant speed its a) velocity is 0 b) inertia is 0 c) none of these d) acceleration is 0

B

While an object near the earth's surface is in free fall, its a) mass decreases b) velocity increases c) mass increases d) acceleration increases

B

Whirl a rock at the end of a string on an ice-covered pond and it follows a circular path. If the string breaks, the tendency of the rock is to a) continue in a circular path b) follow a straight-line path

C

You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact? a) your car b) the bug c) both the same