A land-speed car can decelerate at 9.8 m/s/s. How long does it take the car to come to a stop from a run of 245.8 m/s?

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge