Physics Test 1

An athlete is lifting a load of 150 lbs. using a muscle which normally needs to apply 5 lbs. to lift 1 lb. of weight. How much force is that muscle applying to lift those 150 lbs?

750 lbs

A force of magnitude F = 20 N is applied to two different carts. One cart has a mass m = 10 kg, the second cart has a mass m = 40 kg. What is the acceleration of each of the carts? A. 2 m/s, 0.5 m/s B. 1 m/s, 0.75 m/s C. 2 m/s, 0.1 m/s D. 2 m/s, 2 m/s

A. 2 m/s, 0.5 m/s

An automobile on a highway is an example of A. A one-dimensional system B. A two-dimensional system C. A three-dimensional system D. A four-dimensional system E. A five-dimensional system

A. A one-dimensional system

A load is being lifted by a constant acceleration. The force pulling up the load is A. Larger than the weight B. Equal to the weight C. Smaller than the weight

A. Larger than the weight

A negative distance implies that an object is located A. On the negative side of the reference point B. To the left of the reference point C. Above the reference point D. Below the reference point E. To the right of the reference point

A. On the negative side of the reference point

Non-science which is presenting itself as science is called A. Pseudo-science B. Alternative science C. Scientific fraud D. Crypto-science

A. Pseudo-science

When is a rope more likely to break? A. When the load is lifted B. When the load is lowered

A. When the load is lifted

Assume that a rocket is fueled one day before launch. Assuming the mission clock will start at launch, then fueling time is A. t = -1 day B. t = 0 C. t = +1 day

A. t = -1 day

A car drives off a cliff. As it leaves the cliff, its horizontal velocity component is 5 m/s and its vertical velocity component is 0 m/s. One second later, its horizontal velocity component is still 5 m/s and its vertical velocity component is -10 m/s. What is its horizontal component of acceleration? Its vertical? Horizontal: A. 5 m/s B. 0 m/s C. -10 m/s D. 10 m/s E. -5 m/s Vertical: A. 5 m/s B. 0 m/s C. -10 m/s D. 10 m/s E. -5 m/s

B, C

A car is moving on the highway at 60 m/s. 5 min. later the car moves at 60 m/s in the same direction. What it its acceleration? A. -12 m/s B. 0 m/s C. 12 m/s

B. 0 m/s

If air resistance is neglected, how long will it take for an object falling from rest to reach a speed of 100 m/s? A. 1 s B. 10 s C. 20 s D. 100 s

B. 10 s

A cart has an acceleration of 10 m/s and a mass of 30 kg. What is the magnitude of the force acting on it? A. 10 N B. 30 N C. 300 N D. 3 N

B. 30 N

A cannon shoots a shell straight up at an initial speed of 300 m/s. If air resistance can be neglected, which speed will it have when it comes back down? A. 20 m/s B. 30 m/s C. 300 m/s D. 600 m/s E. 500 m/s

B. 30 m/s

A pseudo-science is A. Any idea system which is not science B. A non-science which claims to be science C. An immature science D. A science which claims to be a religion

B. A non-science which claims to be science

The position of a boat moving on a calm sea is an example of A. A one-dimensional system B. A two-dimensional system C. A three-dimensional system D. A four-dimensional system E. A five-dimensional system

B. A two-dimensional system

The principal advantage of metric units over English units is that A. Metric units are of more convenient size B. Conversions between units are easier C. Metric units are more familiar D. There are fewer metric units to remember than English units

B. Conversions between units are easier

You weigh an object by hanging it from a rope which works by reading the amount of tension. You do this on a moving elevator. Under which of the following circumstances would you expect the scale to read more than the actual weight? A. Elevator moving upward at constant velocity B. Elevator moving upward with constant acceleration C. Elevator moving downward at constant velocity D. Elevator moving downward with constant acceleration

B. Elevator moving upward with constant acceleration

You are lowering a load into a well. The load is attached to a rope, and the load moves with constant velocity. The tension in the rope is A. Larger than the weight B. Equal to the weight C. Smaller than the weight

B. Equal to the weight

You are in an elevator which is moving upward at a constant acceleration of 10 m/s. The floor pushes up against your feet with a force A. Equal to your weight B. Equal to twice your weight C. Less than your weight D. Of zero

B. Equal to twice your weight

You are pushing a crate rightwards with a mass of 10 kg and a force of 50 N. The surface is rough, and the frictional force has a magnitude of 10 N. Where is the friction force pointing? What is the magnitude of the acceleration? A. Rightwards, 4 m/s B. Leftwards, 4 m/s C. Rightwards, 5 m/s D. Leftwards, 5 m/s

B. Leftwards, 4 m/s

Assume you transport a 1 kg mass from Earth to the moon. What would happen to the mass? To the weight? A. Mass changes, weight stays the same B. Mass stays the same, weight changes C. Mass stays the same, weight increases D. Mass increases, weight stays the same

B. Mass stays the same, weight changes

Suppose that you drop two objects from the same height at the same time. Object number one weighs 10 lbs while object number two weights 20 lbs. Aristotle would predict that A. Object 1 would hit the ground long before object 2 B. Object 2 would hit the ground long before object 1 C. They would hit the ground at the same time D. There's no way to tell what will happen

B. Object 2 would hit the ground long before object 1

Assume the x-axis to be an East-West line. Assume the positive direction to be pointing East. Now, a car is moving East with a speed of 30 mph. The driver realizes he forgot something at home. He stops the car, turns around, and starts moving west with a speed of 30 mph. What is his velocity before and after turning around? A. The same B. Positive before, negative after C. Negative before, positive after How about his speed?

B. Positive before, negative after A. The same

After we leave the lecture room the floor is going to A. Sink a bit B. Raise a bit C. Stay the same

B. Raise a bit

What do the police care about? A. Velocity B. Speed C. Don't know, go away, it's early in the morning

B. Speed

Galileo's approach to finding the laws that govern falling objects was to A. Find logical contradictions in the established theory B. Test the predictions of an established theory C. Accept the established theory D. Prove the superiority of his own theory

B. Test the predictions of an established theory

A few weeks ago, a scientific module landed on a comet. One of the major technical hurdles was A. To survive the low temperatures B. To stick to the comet because of its low gravitation C. Not to be crushed by the high gravitation

B. To stick to the comet because of its low gravitation

Assume that a rocket is fueled one day before launch. Assuming the mission clock will start one day before launch, then fueling time is A. t = -1 day B. t = 0 C. t = +1 day

B. t = 0

A mass has a weight of 1 N. That is, Earth exerts a force of 1 N on this mass. How big is the mass? A. 1 kg B. 10 kg C. 0.1 kg

C. 0.1 kg

A projectile is thrown at an angle of 30 degrees with horizontal velocity of 10 m/s and a vertical velocity of 25 m/s. What's the speed of the projectile at the top of its trajectory? A. 0 B. 25 m/s C. 10 m/s

C. 10 m/s

A ball is thrown straight up. We measure time from the instant that it is launched. Which of the following cues might describe when it reaches the top and when it lands? A. 0, 2 B. -2, -4 C. 2, 4 D. 3,1

C. 2, 4

A clay pigeon is fired straight up and reaches its highest point three seconds later. What was its initial speed? A. 3 m/s B. 10 m/s C. 30 m/s D. 300 m/s

C. 30 m/s

A block of mass 120 kg slides on a surface with coefficient of friction u = 0.25. What is the magnitude of the force of friction? A. 150 N B. 200 N C. 300 N D. 400 N E. 4800 N

C. 300 N

A cannon shoots a shell straight up at an initial velocity of 300 m/s. How long will it take for the shell to come back to the launching point? A. 20 s B. 30 s C. 300 s D. 60 s E. 500 s

C. 300 s

A cannon shoots a shell up with an intial vertical velocity component of 500 m/s and an initial horizontal component of 400 m/s. Neglecting air resistance and the curvature of the earth, how far away from the cannon will the shell hit? A. 50,000 m B. 20,000 m C. 40,000 m

C. 40,000 m

The position of a submarine is an example of A. A one-dimensional system B. A two-dimensional system C. A three-dimensional system D. A four-dimensional system E. A five-dimensional system

C. A three-dimensional system

A load is being lowered at a constant velocity. The forces on the load are A. The weight B. An upward tension C. An upward tension and the weight D. A downward tension and the weight

C. An upward tension and the weight

Why, after a snowstorm, do police block off the area next to tall buildings? A. To prevent climate change demonstrations B. To prevent snowball fights C. Because ice and snow may fall from the roof and injure bystanders

C. Because ice and snow may fall from the roof and injure bystanders

Which of the following tasks would require a non-science discipline? A. Designing an airplane B. Programming a computer C. Sentencing a criminal D. Finding a cure for cancer

C. Sentencing a criminal

Which one of the following statements about the theory of evolution is definitely wrong? A. The theory is well-established B. The theory hasn't been disproven C. The theory is a proven fact D. The theory is wrong

C. The theory is a proven fact

How many bombs can an ICBM deliver? A. 1 B. 3 C. Up to 10

C. Up to 10

A ball is thrown straight up and reaches its highest point at 5 m after 1 second, and then it falls down. What is its instantaneous velocity at the instant it reaches its highest point? A. +5 m/s B. -5 m/s C. +10 m/s D. -10 m/s E. 0 m/s

D. -10 m/s

Assume to be pushing a cart with a force of 10 N. If the mass of the cart is 2 kg, what's the acceleration? A. 10 m/s B. 5 m/s C. 2 m/s D. 0.2 m/s

D. 0.2 m/s

Suppose that 5:00 pm is taken to be t = 0. What time would t = -6 hours refer to? A. 11 pm B. 6 pm C. 1 pm D. 11 am E. 3 pm

D. 11 am

Which of the following answers is closest to the weight (on Earth) of a woman who's mass is 50 kg? A. 5 N B. 50 lbs C. 50 N D. 500 N

D. 500 N

Suppose a baseball is thrown with a horizontal velocity component of 30 m/s and a vertical velocity component of 10 m/s. How far will it travel before coming back down to the level at which it was thrown? A. 10 m B. 20 m C. 30 m D. 60 m E. 80 m

D. 60 m

Which of the following units is not appropriate for measuring volume? A. Cup B. Liter C. Pint D. Centimeter E. Milliliter

D. Centimeter

A non-science in Popper's sense is a discipline whose statements are A. Imprecise or fuzzy B. Obviously incorrect C. Not supported by evidence D. Not tentative

D. Not tentative

You are in an elevator which is moving upward at a constant velocity of 10 m/s. The floor pushes up against your feet with a force A. Equal to your weight B. Equal to twice your weight C. Less than your weight D. Of zero

D. Of zero

If you watch astronauts on the moon, you will notice that they could move without difficulty, though they were wearing heavy space suits. Why?

Gravity on the moon is 6x smaller than that of Earth.