Help!:
1. A 14 g coin slides upward on a surface that is inclined at an angle of 16° above the horizontal. The coefficient of kinetic friction between the coin and the surface is 0.23; the coefficient of static friction is 0.31. Find the magnitude and direction of the force of friction under the following circumstances.
(a) when the coin is sliding
.03 N
parallel to the incline
up the incline
down the incline
(b) after it comes to rest
.012 N
parallel to the incline
down the incline
up the incline
2. A 80 kg astronaut and a 1300 kg satellite are at rest relative to the space shuttle. The astronaut pushes on the satellite, giving it a speed of 0.23 m/s directly away from the shuttle. Seven-and-a-half seconds later the astronaut comes into contact with the shuttle. What was the initial distance from the shuttle to the astronaut?
1.725 m
3. Find the orbital speed of a satellite in a circular orbit 2540 km above the surface of the Earth.
215320 km/s
4. The force shown in Figure 7-16 acts on a 1.7 kg object whose initial speed is 0.44 m/s and initial position is x = 0.27 m.
Figure 7-16
(a) Find the speed of the object when it is at the location x = 0.85 m.
.74 m/s
(b) At what location would the object's speed be 0.40 m/s?
.46 m
