Physics 131- Test 2
According to Kepler's First Law, all planets have orbits about the Sun that are
ellipses.
If the radius in which an object moves in uniform circular motion is doubled while the speed remains constant the centripetal force is multiplied by a factor of
1/2
According to Newton's Law of Universal Gravitation, when the distance between the centers of two objects is tripled and the masses remain constant the force between the objects is multiplied by a factor of
1/9
If the height of an object above a reference level is doubled its gravitational potential energy is multiplied by
2
If the speed of an object is doubled, its momentum is multiplied by
2
If the speed of an object in uniform circular motion is doubled while the radius remains constant the centripetal force is multiplied by a factor of
4
If the speed of an object is doubled, its kinetic energy is multiplied by
4
If the velocity of an object is doubled its kinetic energy is multiplied by
4
if the distance a spring is stretched from its equilibrium position is doubled the elastic potential energy of the spring is multiplied by
4
If the distance between a point mass and the pivot point is tripled, the rotational inertia of the object about that point is multiplied by
9
The fundamental unit of work and energy is the
Joule
Which will win the race to the bottom of an incline: a disk or a ring with the same mass and radius?
The disk
A disk and a ring have equal mass and radius and are both rotating about an axis through their centers. Which has the greatest rotational inertia?
The ring
Which identical rod has the smallest rotational inertia, the one rotating about its end, or the one rotating about its center?
The rod rotating about its center.
If an artificial satellite is orbiting about the Earth between the Earth and the Moon, how does its period of rotation compare to the Moon's period?
The satellite has a shorter period of rotation than the Moon.
Which is stronger, the Earth's pull on the Moon, or the Moon's pull on the Earth?
They are the same.
Why is the recoil less if a person holds a gun tightly against the shoulder?
Your mass becomes part of the system, and since momentum is conserved, the recoil velocity of the gun & person is reduced.
A pendulum moves with the greatest velocity
at the bottom of its swing.
Increasing the mass of an object without changing its velocity
increases its momentum and its kinetic energy
The principle of conservation of momentum
is valid only if the net external force acting on the system is zero.
A perfectly elastic collision is one in which
kinetic energy is conserved.
If an equivalent amount of work is done in a shorter period of time
more power is required.
Kinetic energy is energy that an object possesses because of its
motion
The centripetal force on an object in uniform circular motion
points toward the center of the circle.
The purpose of an airbag in an automobile is to
prolong the time of impact and thereby reduce the force of impact.
Which of the following is NOT a unit for rotational displacement?
radians/second
Simple harmonic motion
repeats itself in equal intervals of time.
Meredith sits in the middle of a merry-go-round that her brother Kiel has given a push. If Meredith moves to the outer edge of the merry-go-round, it will
slow down
The impulse/momentum theorem states that the impulse is equal to
the change in momentum
A perfectly inelastic collision is one in which
the objects stick together after the collision.
Work is defined as
the product of force and the distance through which the force acts.
Impulse is calculated as
the product of force and the time interval.
In uniform circular motion
the speed of the object is constant.
The principle of conservation of energy states that if no work is done on a system by a nonconservative force
the total mechanical energy is a constant.
If two children sit on a seesaw and one is twice as heavy as the other, in order to achieve balance the lighter child must sit
twice as far from the fulcrum.