1. asteroid is moving along a straight line. A force acts along the displacement of the asteroid and slows it down. The asteroid has a mass of 5.3x 104 kg, and the force causes its speed to change from 7900 to 5000m/s. (a) What is the work done by the force? (b) If the asteroid slows down over a distance of 1.8 10 m determine the magnitude of the force.
2. The drawing shows two boxes resting on frictionless ramps. One box is relatively light and sits on a steep ramp. The other box is heavier and rests on a ramp that is less steep. The boxes are released from rest at A and allowed to slide down the ramps. The two boxes have masses of 14 and 38 kg. If Aand B are 6.0 and 1.5 m, respectively, above the ground, determine the speed of (a) the lighter box and (b) the heavier box when each reaches B. (c) What is the ratio of the kinetic energy of the heavier box to that of the lighter box at B.
3. A small lead ball, attached to a 1.20-m rope, is being whirled in a circle that lies in the vertical plane. The ball is whirled at a constant rate of three revolutions per second and is released on the upward part of the circular motion when it is 1.4 m above the ground. The ball travels straight upward. In the absence of air resistance, to what maximum height above the ground does the ball rise?
4. A pendulum consists of a small object hanging from the ceiling at the end of a string of negligible mass. The string has a length of 0.78 m. With the string hanging vertically, the object is given an initial velocity of 1.5 m/s parallel to the ground and swings upward in a circular arc. Eventually, the object comes to a momentary halt at a point where the string makes an angle O with its initial vertical orientation and then swings back downward. Find the angle O.
5. You are working out on a rowing machine. Each time you pull the rowing bar (which simulates the oars) toward you, it moves a distance of 0.800 m in a time of 1.70s. The readout on the display indicates that the average power you are producing is 81.0 W. What is the magnitude of the force that you exert on the handle?
6. A water slide is constructed so that swimmers, starting from rest at the top of the slide, leave the end of the slide traveling horizontally. As the drawing shows, one person hits the water 5.00 m from the end of the slide in a time of 0.545s after leaving the slide. Ignore friction and air resistance, find the height H in the drawing.