In the picture below, how could the man make it easier to lift the stone with the lever?
a) use two boards instead of one board.
b) move the fulcrum farther away from the stone.
c) move the stone to farthest end of the board.
d) move the fulcrum closer to the stone.

What object a collides with object b and bounces back its final momentum is?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j.b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Sound travels slower in colder air that it does in warmer air. make a claim about the effect of air temperature on the speed of sound. support your claim with evidence