1. (15 points)
block a of mass 4.0 kg is pulled along a horizontal table by a force of 15 n, which is applied
by a light string that passes over a light frictionless pulley, as shown above. the coefficient
of kinetic friction betveen the block and the surface is 0.25.
(a) on the dot below, which represents the block, draw and label the forces (not components)
that act on the block as it is pulled across the table.

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

Explain why electric current cannot exist if a current doesn't have a voltage source.

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)