A 2.0-kg block starts with a speed of 10 m/s at the bottom of a plane inclined at 37° to the horizontal. The coefficient of sliding friction between the block and plane is μk = 0.30. (a) Use the work-energy principle to determine how far the block slides along the plane before momentarily coming to rest. (b) After stopping, the block slides back down the plane. What is its speed when it reaches the bottom? (Hint: For the round trip, only the force of friction does work on the block.)

A horizontal force of magnitude 41.3 N pushes a block of mass 3.92 kg across a floor where the coefficient of kinetic friction is 0.576. (a) How much work is done by that applied force on the block-floor system when the block slides through a displacement of 4.79 m across the floor? (b) During that displacement, the thermal energy of the block increases by 40.5 J. What is the increase in thermal energy of the floor? (c) What is the increase in the kinetic energy of the block? (a) Number i Units (b) Number i Units (c) Number i Units

A small block of mass 230 g starts at rest at A, slides to B where its speed is v = 7.8 m/s, then slides along the horizontal surface a distance 13 m before coming to rest at C. (See below.) 4.0 m B 13 m (a) What is the work of friction along the curved surface (in J)? (b) What is the coefficient of kinetic friction along the horizontal surface?

A block of mass m is dropped onto a relaxed vertical spring with spring constant k (see the figure). The block becomes attached to the spring and compresses the spring a distance d before momentarily stopping. Assuming that friction is negligible, while the spring is being compressed, what work is done on the block by (a) the gravitational force on it? W = mg d (b) the spring force? W = 1 k d² 2 (c) What is the speed of the block just before it hits the spring? v = 2gd- k d² ✓ m | NOTE: State your answers in terms of the given variables and g.