1.
According to Kepler's laws, the paths of planets about the sun are
2.
Both Newton and Kepler considered forces on the planets. Kepler hypothesized the direction of the forces was
A.
Along their directions of travel.
B.
C.
3.
Which of the following is not a vector quantity?
A.
B.
C.
D.
None are vector quantities.
E.
All are vector quantities.
4.
An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of
5.
An airplane travels at 141 km/h toward the northeast. What is its component of velocity due north?
6.
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its vertical component of velocity
7.
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its horizontal component of velocity
8.
A stone is thrown horizontally from the top of a cliff. One second after it has left your hand, its vertical distance below the top of the cliff is
9.
Throw an object upward at a 45 degree angle. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 second, it is
A.
About 5 m below the straight line.
B.
About 10 m below the straight line.
C.
About 15 m below the straight line.
10.
Roll a bowling ball off the edge of a table. As it falls, its horizontal component of velocity
11.
A bullet fired horizontally from a rifle begins to fall
A.
As soon as it leaves the barrel.
B.
After air friction reduces its speed.
C.
12.
A projectile is launched vertically upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is
13.
An Earth satellite is simply a projectile
A.
Freely falling around the Earth.
B.
Floating motionless in space near the Earth.
C.
Approaching the Earth from outer space.
14.
Earth satellites are typically more than 100 km high so as to be above the Earth's
15.
A projectile is fired horizontally in a region of no air resistance. The projectile maintains its horizontal component of velocity because
A.
It is not acted on by any forces.
B.
It is not acted on by any horizontal forces.
C.
It has no vertical component of velocity to begin with.
D.
The net force acting on it is zero.
E.
16.
A hunter on level ground fires a bullet at an angle of 10 degrees above the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?
A.
B.
C.
Both hit at the same time.
17.
A hunter on level ground fires a bullet at an angle of 2 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?
A.
B.
C.
Both hit at the same time.
18.
A bullet fired horizontally over level ground hits the ground in 0.5 second. If it had been fired with twice the speed in the same direction, it would have hit the ground in
19.
An object is dropped and freely falls to the ground with an acceleration of 1 g. If it is thrown upward at an angle instead, its acceleration will be
20.
A projectile is launched at ground level an angle of 15 degrees above the horizontal and lands down range. What other projection angle for the same speed would produce the same down-range distance?
21.
A projectile is fired into the air at an angle of 50 degrees with the ground and lands on a target that is at the same level at which the projectile started. It will also land on the target if it is fired at an angle of
22.
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?
23.
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)
A.
B.
C.
Both hit at the same time.
24.
After a rock thrown straight up reaches the top of its path and then falls a short distance, its acceleration is (neglect air resistance)
A.
Greater than when it was at the top of its path.
B.
Less than when it was at the top of its path.
C.
The same as it was at the top of its path.
25.
A projectile is fired vertically from the surface of the Earth at 8 km/s. The projectile will
A.
Go into circular orbit about the Earth.
B.
Rise and fall back to the Earth's surface.
C.
Follow an uncertain path.
D.