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A small car meshes with a large truck in a head-on collision.  Which one undergoes the greater change in momentum?

If you push an object twice as far while applying the same force, you do

You throw a ball straight up.  Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.

A difference between electric forces and gravitational forces is that gravitational forces are not affected by 

Two objects move toward each other because of gravity. As the objects get closer and closer, the acceleration of each

Consider a string with several rocks tied along its length at equally spaced intervals. You whirl the string overhead so that the rocks follow circular paths. Compared to a rock in the middle of the string, a rock at the outer end moves

A hang glider and its pilot have a total mass equal to 120 kg. While executing a 360º turn, the glider moves in a horizontal circle with an 8 m radius. The glider’s speed is 10 m/s. What is the net force on the hang glider?

The kinetic friction force between a 60.0-kg object and a horizontal surface is 50.0 N.  If the initial speed of the object is 25.0 m/s, what distance will it slide before coming to a stop?

Find the force on the Moon (Mm= 7.35x1022kg due to the gravitational attraction of the Earth(Me= 5.98x 1024 kg).  The distance to the Moon is  3.82 × 108 m. G = 6.67 x 10-11 N m2/ Kg2 

In a hydrogen atom in its lowest energy state, the single electron and the single proton are separated by a tiny distance called the Bohr radius, 5.29×10−11 m. The proton carries a charge e = 1.60×10−19 C. (a) What is the strength of the electric field generated by the proton at the Bohr-radius distance? K = 8.9 x 109  N m 2/C2