Final - Physics Chapter 10
If a satellite's radial velocity is zero at all times, its orbit must be
circular.
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its vertical component of velocity
decreases.
Consider a moon that orbits one of our most distant planets in an elliptical path. The distance that the moon covers each day is
greatest when the moon is closest to the planet.
A "weightless" astronaut in an orbiting shuttle is
like the shuttle, pulled by Earth's gravitation.
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its horizontal component of velocity
remains unchanged.
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 it was at the top of its path.
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 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
5 m.
An Earth satellite is in an elliptical orbit. The satellite travels fastest when it is
nearest the Earth.
Earth satellites are typically more than 100 km high so as to be above the Earth's
atmosphere.
The radial velocity of an Earth satellite is its velocity
perpendicular to the surface of the Earth.
An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of
141 km/h.
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
about 5 m below the straight line.
A bullet fired horizontally from a rifle begins to fall
as soon as it leaves the barrel.
A projectile is fired vertically from the surface of the Earth at 5 km/s. The projectile will
rise and fall back to the Earth's surface.
Acceleration due to gravity on the moon is less than on Earth, and the moon is smaller than Earth. So compared to an Earth satellite, a satellite in close orbit about the moon would travel
slower.
Which of the following is not a vector quantity?
speed
Without air resistance, a projectile fired horizontally at 8 km/s from atop a mountain would
(All of these
The circular path of a satellite orbiting the Earth is characterized by a constant
All of these
It takes Pluto a longer time to orbit the sun than the Earth does because Pluto
Choices A and B are both correct
A satellite describes an elliptical orbit about a planet. The satellite travels much faster when it is directly over a
None of the above choices affects its speed very much.
What prevents satellites such as the space shuttle from falling?
Nothing; they are continually falling as they orbit the Earth.
What prevents satellites such as a space shuttle from falling?
nothing; they're falling continuously all around the earth
The fastest moving planet in a solar system is
the planet nearest the sun.
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
0.5 s.
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
1 g downward.
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
An airplane travels at 141 km/h toward the northeast. What is its component of velocity due north?
100 km/h
The ground speed of an airplane that has an airspeed of 200 km/h when it is in a 200-km/h crosswind is
283 km/h.
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
40 degrees.
A projectile is launched vertically upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is
50 m/s.
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?
75 degrees
Our moon travels the fastest as it orbits the Earth when it is
closest.
An Earth satellite is simply a projectile
freely falling around the Earth.
A projectile is fired horizontally in a region of no air resistance. The projectile maintains its horizontal component of velocity because
it is not acted on by any horizontal forces.
A lunar month is about 28 days. If the moon were closer to the Earth than it is now, the lunar month would be
less than 28 days.
A woman on the surface of the Earth has a mass of 50 kilograms and a weight of 490 newtons. If the woman were floating freely inside a space habitat far away from Earth, she would have
less weight and the same mass.
A lunar month is about 28 days. If the moon were farther from the Earth than it is now, the lunar month would be
more than 28 days.
The tangential velocity of an Earth satellite is its velocity
parallel to the surface of the Earth.
Roll a bowling ball off the edge of a table. As it falls, its horizontal component of velocity
remains constant.
A projectile is fired vertically from the surface of the Earth at 8 km/s. The projectile will
rise and fall back to the Earth's surface.
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?
the dropped one
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?
the fired one
The speeds of the planets about the sun depend on
their distances from the sun.
Planets would crash into the sun if it weren't for
their tangential velocities.