Physics 1310 Echon Test 2 Review

Your pet hamster sits on a record player that has constant angular speed. If the hamster moves to a point twice as far from the center, then its linear speed

doubles

According to Kepler, the speed of a planet is slowest when it is

farthest from the Sun

A bicycle that travels twice as fast as another when braking to a stop will skid

four times as far

The force of Earth's gravity on a capsule in space increases as it comes closer. When the capsule moves to half its distance, the force toward Earth is then

four times greater

As two objects moving toward each other due to gravity get closer, the acceleration of each

increases

When the distance between two stars decreases by one-third, the force between them

increases to nine times as much

A ball rolled along a horizontal surface maintains a constant speed because

no horizontal force acts on it

Newton discovered

that gravity is universal

Nellie tosses a ball upward at an angle. Assuming no air resistance, which component of velocity changes with time?

the vertical component

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?

the bug your car *both the same

No work is done by gravity on a bowling ball that rolls along a bowling alley because

the force on the ball is at right angles to the ball's motion

A black hole is

the remains of a giant star that has undergone gravitational collapse

The mass of a ball moving at 3 m/s with a momentum of 48 kg m/s is

16 kg.

A 2-kg box of taffy candy has 40 J of potential energy relative to the ground. Its height above the ground is

2 m

The circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second then its linear speed is

2 m/s

The average braking force of a 1000-kg car moving at 10 m/s braking to a stop in 5 s is

2000 N.

The speed of a 4-kg ball with a momentum of 12 kg m/s is

3 m/s

The work done in pushing a TV set a distance of 2 m with an average force of 20 N is

40 J

If there were no gravity a stone thrown upward at 45 degrees would follow a straight-line path. But because of gravity, at the end of 1 second, the stone is actually

5 m below the straight line

It there were no gravity a stone thrown upward at 45 degrees would follow a straight-line path. But because of gravity, at the end of 1 second, the stone is actually

5 m below the straight line.

A 5000-kg freight car collides with a 10,000-kg freight car at rest. They couple upon collision and move at 2 m/s. What was the initial speed of the 5000-kg car?

6 m/s

A bullet is fired horizontally with an initial velocity of 300 m/s from a 20-m high tower. If air resistance is negligible, the bullet hits downrange about

600 m.

A projectile is launched from ground level at 15° above the horizontal and lands downrange. What other projection angle for the same speed would produce the same down-range distance?

75°

A 2-kg ball is held 4 m above the ground. Relative to the ground its potential energy is

80 J

A difference between linear momentum and angular momentum involves A.) a radial distance B.)two types of speed C.) both of these

C.) both of these

Which of these vary for satellites in elliptical orbits? A.) momentum. B.) speed. C.) kinetic energy. D.) all of the above E.) none of the above

D.) all of the above

You can experience weight A.) in an accelerating elevator away from Earth. B.) in a rotating habitat in space. C.)standing on Earth's surface. D.) all of the above

D.) all of the above

The impulse-momentum relationship is a direct result of

Newton's 2nd law

The conservation of momentum is most closely related to

Newton's 3rd law.

It is correct to say that impulse is equal to

a corresponding change in momentum.

A dropped ball gains speed because

a gravitational force acts on it

Multiple the equation for linear momentum by radial distance r and you have

angular momentum

The net force exerted on a car traveling in a circular path at constant speed is

directed toward the center of the curve

The work you do when pushing a shopping cart twice as far while applying twice the force is

four times as much

Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has

four times the kinetic energy

According to Newton, the greater the masses of interacting objects, the

greater the gravitational force between them

A satellite coasting at constant speed in a circular orbit

is nevertheless accelerating

A same-size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater

momentum.

According to Newton, when the distance between two interacting objects doubles, the gravitational force is

one-quarter

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

remains constant

When railroad tracks make a curve, the outer track is longer. This means a wheel that rides on the outer track needs to somehow

roll faster than the wheel on the inner track

A ring, a disk, and a solid sphere begin rolling down a hill together. Which reaches the bottom first?

sphere

Compared with falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the

stopping time is longer on the carpet

If Alex wishes to rotate his skateboard, then he must apply a

torque

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is

twice as much

Relative to an initial height, an object raised twice as high has a gravitational potential energy

twice as much

The work you do when pushing a shopping cart a given distance while applying twice as much force is

twice as much

The work you do when pushing a shopping cart twice as far while applying the same force is

twice as much

Danny Diver weighs 500 N and steps off a diving board 10 m above the water. Danny hits the water with kinetic energy of

5000 J

You experience weightlessness A.) in a freely falling elevator. B.) in the absence of a supporting surface. C.) momentarily when you step off a chair. D.) all of the above

D.) all of the above

An outcome of universal gravitation is that A.)prediction and discovery of planets. B.) its discovery prompted other laws of nature. C.) planets aren't cubes with sharp corners. D.)all of the above

D.)all of the above

A cannonball has more kinetic energy than the recoiling cannon from which it is fired because the force on the ball

acts over a longer distance

If the Sun were twice as massive A.) the pull of Earth on the Sun would double B.) it's pull on Earth would double C.) both of these

both of these

According to Kepler, the orbital period of a planet is directly proportional to the

cube of the planet's average distance from the Sun

In comparison with other fundamental forces, the universal gravitational constant G indicates that gravity is

very weak

An Earth satellite in an elliptical orbit has its smallest speed

when farthest from Earth