Chapter 10 test

Conservation of energy applies to satellites in

circular and elliptical orbit

The kinetic energy of a planet is maximum when its

closest to the sun

A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, how far downrange will the bullet be 1 second later?

100 m

In the absence of air resistance, at what other angle will a thrown ball go the same distance as one thrown at an angle of 75 degrees?

15 degrees

When air drag affects the motion of projectiles, they don't travel

-as far -as high BOTH OF THESE

In order to find the components of a vector, you should

-draw the vector with correct magnitude and orientation -measure the sides of the rectangle -draw a rectangle so that the vector is the diagonal ALL OF THE ABOVE

The circular path of a satellite orbiting the Earth is characterized by a constant

-speed -acceleration -radial distance ALL OF THE ABOVE

When representing velocity as a vector

-the direction of the arrow shows the direction of motion -the length of the arrow represents the speed -the length of the arrow is drawn to a suitable scale ALL OF THE ABOVE

a projectile launched horizontally hits the ground in .8 seconds. If it had been launched with a much higher speed in the same direction, it would have hit the ground (neglecting Earth's curvature and air resistance) in

0.8 s

a ball is thrown straight upward at 10 m/s. Ideally (no air resistance), the ball will return to the thrower's hand with a speed of

10 m/s

a ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation 5 m above the ground level, The ball lands 20 m downrange. The player's pitching speed is about

20 m/s

Two projectiles are fired from ground level at equal speeds but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. The projectile to hit the ground first will be the one fired at (neglect air resistance)

30 degrees

a cannonball is launched from the ground at an angle of 30 degrees above the horizontal and a speed of 30 m/s. Ideally (no air resistance) the ball will land on the ground with a speed of

30 m/s

in the absence of air resistance, the angle at which a thrown ball will go the farthest is

45 degrees

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

5 m below the straight line

A cannonball fired at some angle into the air. IN the first second it moves 5 meters horizontally. Assuming it doesn't hit the ground and air resistance is negligible, how far does it move horizontal in the next second?

5 meters

a baseball is hurled into the air and at an angle of 30 degrees above the horizontal and lands on a target that is the same level as that where the baseball started. the baseball will also land on the target if its thrown at an angle of

60 degrees.

a cannonball is launched from a tower. If the cannon has a barrel velocity of 60 m/s, where will the cannone be 1 second later?

60 m downward

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 cannon with a barrel velocity of 140 m/s launches a cannonball horizontally from a tower. Neglecting air resistance, how faar vertically will the callone ball have fallen after 4 seconds?

80 m

a ball thrown in the air will never go as far as physics ideally would predict because

Air friction slows the ball

In the absence of air friction, the horizontal component of a projectile's velocity doesn't change as the projectile moves.

Always true

when the potential energy of a satellite decreases

its kinetic energy correspondingly increases

which of the following would NOT be considered a projectile

a cannonball rolling down a slope

Ideally, a ball is thrown up at an angle and lands downrange. Because of air resistance, the distance reached is

less

in the absence of air friction, the vertical component of a projectile's velocity doesn't change as the projectile moves.

always false

Project a cannonball from atop Newton's hypothetical mountain at 8 km/s and it orbits Earth. Project it at 9 km/s and the shape of the orbit is

an ellipse

at what part of a path does a projectile have a minimum vertical speed?

at the top of its path

A ball rolls off the edge of a table at the same time another ball drops vertically from the same table. The ball to hit the floor first is the

both hit at the same time.

A lunar month is about 28 days. If the Moon were closer to Earth than it is now, the lunar month would be

less than 28 days

a ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is

entirely horizontal

according to kepler, the speed of a planet is slowest when it is

farthest from the sun

An Earth satellite is simply a projectile

freely falling around the earth

An object is dropped and falls freely to the ground with an acceleration of g. If it is thrown upward at an angle instead, its acceleration would be

g downward

a projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it

is not acted on by any horizontal forces.

A projectile is launched vertically upward at 50 m/s. If air resistance does affect motion, then its speed upon returning to its starting point is

less than 50 m/s

An object is thrown vertically into the air. in this case air resistance affects motion. Compared with its time for ascent, the time for its decent is

longer

a scalar is a quantity that has

magnitude

A vector is a quantity that has

magnitude and direction

Dr. Chuck projects a ball horizontally from a lab bench. The ball lands on a bullseye marked on the floor a horizontal distance equal to the ball's initial speed

multiplied by its time in the air.

An Earth satellite is in an elliptical orbit. The satellite travels fastest when it is

nearest Earth

at the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. Which ball hits the ground first?

neither. they both hit the ball at the same time

At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. Which ball hits the ground first?

neither. they both hit the ground at the same time.

in chapter 2, you learned about "hang time" the time a jumper's feet are off the ground in a vertical jump. if the jumper runs horizontally and has the same vertical component of takeoff velocity, hang time will be

no different

Jose can jump vertically 1 meter from his skateboard when it is at rest. When the skateboard is moving horizontally, Jose can jump

no higher

An astronaut at Earth's surface has a mass of 50 kg and a weight of 500 N. If she were floating freely inside a space habitat in remote space, she would have

no weight and the same mass

Acceleration is greater for a satellite when it is at the

perigee

A projectile that is fired vertically from the surface of Earth at 5 km/s will

rise and fall back to Earths surface

a hunter on level ground fires a bullet at an angle of 10 degrees BELOW the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?

the one fired

The fastest moving planet in a solar system is

the planet nearest the sun

After a rock thrown straight up reaches the top of its path and then falls a short distance, its acceleration is (neglect air resistance)

the same as at the top of its path.

After a rock that is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is (neglecting air resistance)

the same as when it was at the top of its patg

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

the vertical component

the horizontal component of a projectile's velocity is independent of

the vertical component of its velocity