A luge and its rider, with a total mass of 79.0 kg, emerge from a downhill track onto a horizontal straight track with an initial speed of 31.0 m/s. If a force slows them to a stop at a constant rate of 1.50 m/s², (a) what magnitude F is required for the force, (b) what distance d do they travel while slowing, and (c) what work W is done on them by the force? What are (d) F, (e) d, and (f) W if they, instead, slow at 3.00 m/s²? (a) Number (b) Number 118.5 320.33 (c) Number i Units Units Units N m

A large cruise ship of mass 6.00 ✕ 107 kg has a speed of 12.4 m/s at some instant. (a) What is the ship's kinetic energy at this time?                           J(b) How much work is required to stop it? (Give the work done on the ship. Include the sign of the value in your answer.)                                                 J(c) What is the magnitude of the constant force required to stop it as it undergoes a displacement of 3.40 km?                             N

A person drags a sled across a frozen lake to town. The surface of the lake is quite smooth and slippery (so the friction from the ice can be neglected), but he has studded boots with nails driven through the soles (from the inside) so he can walk across the ice without slipping. As he nears his destination, he begins to slow the sled down by pushing in a direction opposite the velocity of the sled. During this process, the work he is doing on the sled is: Positive   Not enough information is given   Negative   Zero

A cord is used to vertically lower an initially stationary block of mass M = 4.9 kg at a constant downward acceleration of g/7. When the block has fallen a distance d = 2.4 m, find (a) the work done by the cord's force on the block, (b) the work done by the gravitational force on the block, (c) the kinetic energy of the block, and (d) the speed of the block. (Note : Take the downward direction positive) (a) Number Units (b) Number Units (c) Number Units (d) Number Units