Physics 1310 Ch 6-10 Quizzes

If the distance between two asteroids doubled, how would the the gravitational force between those two asteroids be affected?

The force would be a quarter what it was

A machine does 500 J of work in 20 s. What is the power of the machine?

25 W

A fish swims toward and swallows a smaller fish at rest. If the larger fish has a mass of 5 kg and swims 1 m/s toward a 2-kg fish, what is the velocity of the larger fish immediately after lunch? Ignore the effects of water resistance.

1/6 m/s

A 6 kg bicycle moving at 4 m/s brakes to a stop in 2 s. What's the average braking force?

12 N

How much work is done in lifting a 500-N barbell 3 m above the floor in 5 seconds?

1500 J

A projectile is launched upward at an angle of 60° from the horizontal and strikes the ground a certain distance downrange. If air resistance is neglected, for what other angle of launch at the same speed would this projectile land just as far away?

30°

How much net work is done on a 1-kg object when it speeds up from 0 m/s to 8 m/s?

32 J

Compared with driving at 30 km/h, how much distance do you need to stop when you are driving at 60 km/h?

4 times as much distance

A projectile falls beneath the straight-line path it would follow if there were no gravity. How many meters does it fall below this line in the first second?

5 m

A 20-kg mass moving at a speed of 4 m/s has a momentum of

80 kg m/s

Astronauts in the international space station appear to float in space. Which of the following best describes the reason.

Astronauts have no apparent weight in orbit because they are falling together with their space station.

The Moon does not crash into Earth because

Moon has a sufficient tangential speed.

A mouse slides down on a ramp. Which of the following increases with increasing slope of the ramp?

The component of the weight of the mouse that is parallel to the slope.

Why is it important that satellites are launched to altitudes of 150 kilometers or higher?

To avoid air resistance

When a dish falls, will the force on the dish be less if it lands on a carpet than if it lands on a hard floor

Yes, force will be less on a carpet

When a box is lifted straight upward, does gravity do work on it?

Yes, it does negative work.

You're riding a roller coaster that is going around a vertical loop-the-loop. You feel heavier at the bottom of the loop because

You apparent weight is greater than your actual weight.

If you weigh yourself in an elevator, you'll weigh less when the elevator

accelerates downward

Inside a freely-falling runaway elevator, your

apparent weight is zero.

In the absence of external forces, momentum is conserved in

both elastic and inelastic collisions

The bob of a simple pendulum has its maximum kinetic energy at the

bottom of its swing.

If you push with the same force on an object for twice as much time, the impulse delivered to the object will be

doubled

A freight train rolls along a track with considerable momentum, if its total mass is doubled and it rolls twice as fast, its momentum will be

four times as much.

When an object is in a state of weightlessness, that means

it has no support force.

When the speed of a bicycle becomes twice as much, which of the following also doubles?

its momentum

When you toss a projectile sideways, it curves as it falls. It will be an Earth satellite if the curve it makes

matches the curved surface of Earth.

If the masses of two planets are each somehow doubled, the force of gravity between them

quadruples.

As soon as a bowling ball rolls off the edge of a table its horizontal component of velocity

remains constant.

A ball is tossed upward at an angle to the horizontal. Neglecting air drag, the acceleration along its path is

straight downward.

A 45-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 3 meters in the same time. Which gains more gravitational potential energy?

the 25-kg sack.

Assume a fast-moving car can be stopped by either a cement wall or a large haystack. Compared to hitting a cement wall, when the fast-moving car hits a large haystack, it experiences

the same change in momentum.

A ball is thrown upward at an angle to the horizontal and caught when it returns to its initial height. Compared with its initial speed and neglecting air resistance, the speed with which it is caught is

the same.

If the gravitational force between an object and Earth is 50 N,

the weight of the object is 50 N.