## What is the change in thegravitational potential energy of the snowball–Earth system during the flight?

1.50 kg snowball is fired from a cliff 12.5 m high. The snowball’s initial velocity is 14.0 m/s,directed 41.0o above the horizontal. (i) (a) How much work is done on the snowball by thegravitational force during its flight to the flat ground below the cliff? (b) What is the change in thegravitational potential energy of the snowball–Earth system during the flight? (c) If that gravitationalpotential energy is taken to be zero at the height of the cliff, what is its value when the snowballreaches the ground? (ii) (a) Now for the same data given above, using energy techniques, find thespeed of the snowball as it reaches the ground below the cliff. What is that speed (b) if the launchangle is changed to 41.0o below the horizontal and (c) if the mass is changed to 2.50 kg?

### design suitable bearings to support the load for at least 5E8 cycles at 1 200 rpm using deepgroove ball bearings.

The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in row (a) of Table P11-1, and the corresponding diameter of shaft found in Problem 10-19,….

### Find the minimum film thickness for a long bearing with the following data: 30-mm dia, 130 mm long, 0.0015 clearance ratio, 1 500 rpm, ISO VG 100 oil at 200°F, and supporting a load of 7 kN.

1.       A paper machine processes rolls of paper having a density of 984 kg/m3. The paper roll is 1.50-m OD X 22-cm ID X 3.23-m long and is on a simply supported, 22-cm OD, steel….

### Find the minimum film thickness for a bearing with these data: 30-mm dia, 25 mm long, 0.0015 clearance ratio, 1 500 rpm, ON = 30, ISO VG 220 oil at 200°F.

1.       Problem 7-12 estimated the volume of adhesive wear to expect from a steel shaft of 40 mm dia rotating at 250 rpm for 10 years in a plain bronze….