Gravity
Throw an object at an angle upward. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 s, it is
5 m below the straight line
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 downrange
A "weightless" astronaut in on orbiting shuttle is
Like the shuttle, pulled by earth's gravitation
Acceleration is greatest for a satellite when it is at the
Perigee
A ball is thrown upwards and caught when it comes back down. Neglecting air resistance, the speed with which it is caught is
The same as the speed it had when thrown upward
A satellite near Earth makes a full circle in about 90 minutes. How long would a satellite located as far away as the Moon take to orbit Earth?
about 28 days
An object is placed exactly halfway between the Earth and moon. The object will fall toward the
earth
The force of gravity does work on a satellite when it is in
elliptical orbit
A hunter aims a rifle at an angle of 10° above the horizontal. The hunter fires a bullet while simultaneously dropping another bullet from the side of the rifle. Which bullet hits the ground first?
the dropped one
When the distance between two stars decreases by half, the force between them
increases to four times as much
Two objects move toward each other because of gravitational attraction. As the objects get closer and closer, the acceleration between them
Increases
Minimal orbit speed about Earth is about 8 km/s. Minimal orbital speed about Mercury would be
Less than 8km per second
Tangential velocity is velocity
parallel to the surface of the Earth
A stone is thrown horizontally from the top of a cliff. Two seconds after it has left your hand its vertical distance below the cliff is
20 m
A projectile is fired horizontally in a region of no air resistance. The projectile maintains its horizontal component of speed because it
is not acted on by any horizontal forces
Minimal orbital speed about the Earth is about 8 km/s. Minimal orbital speed about the moon would be
less than 8 km/s
According to newton, the greater the distance between masses of interacting objects, the
less the gravitational force between them
Compared with the period of satellites in orbit close to earth, the period of satellites in orbit far from earth is
longer
Each of us weighs a tiny bit less inside the ground floor of a skyscraper than we do on the ground away from the skyscraper because the
mass of the building attracts us upward slightly
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises its horizontal component of velocity
remains unchanged
Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them is also doubled, then the force between them is
same
Ignoring air drag, what is the maximum speed that can be given to a horizontally moving tennis ball as it clears the net 1.25 m high to remain within the edge of the court, which is 12.0 m distant?
24.0 m/s
An Earth satellite is in an elliptical orbit. The satellite travels fastest when it is
At the perigee
Communication and weather satellites always appear at the same place in the sky. This is because these satellites are
Geosynchronous
According to newton, the greater the masses of interaction objects, the
Greater the gravitational force between them
It takes Pluto a longer time to orbit the sun than the Earth does because Pluto
Has further to go and goes slower
Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them
increases