1. A swimmer can swim in still water at a speed of 9.50 m/s. She intends to swim directly across a 15.0 m wide river that has a current of 3.75 m/s.
a) what must her heading be?
b) what is her velocity relative to the bank of the river?
c) how long does it take her to cross the river?
2. What force must be exerted on an electron (mass=9.11x10^-31 kg) to move it from a state of rest to a speed of 3.5 x 10^7 m/s in a distance of 0.75 m?
3. Two satellites of equal mass are orbiting the Earth 75.0 m apart. If the gravitational force between them is 1.50 x 10^-7 N, find the mass of each.
4. A 15,000 N vehicle is parked on an incline that makes an angle of 15.0 degrees with the horizontal. If the maximum for the vehicle's brakes can withstand is 10,000 N, will the vehicle remain at rest?
5. A traffic light is supported by two wires positioned 110 degrees apart. If the maximum tension in each wire is 750 N, what is the maximum weight of the light they can support?
6. A 100-kg commuter is standing on a train accelerating at 3.70 m/s^2. What coefficient of friction must exist between the commuter's feet and the train's floor to avoid sliding?
7. A 65.0 kg crate is to be accelerated at 7.00m/s^2 up an incline making a 25.0 degree angle with the horizontal. If the coefficient of friction between the crate and the incline is 0.200, how much force is required?
8. A 400.0 N child and a 300.0 N child sit on either end of a 2.00 m long seesaw. Where along the seesaw should the pivot be placed to ensure rotational equilibrium?
9. A 250.0 N child and a 200.0 N child are attempting to lift a 500.0 N box sitting 1.00 m from the pivot of their 3.00 m long lever. If the lighter child stands on the end of the lever, where does the heavier child have to stand to balance the lever and lift the box?
10. A looping roller coaster ride at an amusement park has a radius of curvature of 7.50 m. At what minimum speed must the coaster be traveling at the top of the curve so the passengers will not fall out?
11. A 25.0 kg child moves with a speed of 1.93 m/s when sitting 12.5 m from the center of a merry-go-round. Calcuate: a) the centripetal acceleration and b) the centripetal force.
12. A merry go round has a mass of 500.0 kg and radius of 2.00m What tangential force must be applied to change its speed from 0.00 to 2.5 rad/s in 5.0 s? The frictional force is 75.0 N.
13. A spinning bicycle wheel 65.0 cm in diameter is rotating at 2.00 rev/s and comes to rest in 15.0 s. What is the angular acceleration of the wheel?
14. How much work is done in pushing a 45.5 kg wooden truck a distance of 9.75 m across the floor is the coefficient of friction is 0.250?
15. A 0.0 kW motor is 80% efficient and moves a lawn tractor at a constant 1.2 m/s. What force is being apllied to the tractor by the motor?
16. A 65.0 kg diver is poised 10.0 m above the surface of a pool. Calculate:
a) the diver's potential energy relative to the pool's surface and
b) the diver's velocity at the pool's surface.Try to solve these challenging problems! Bet you cant!?If you would like to send me a check $50 per hr labor and $100 to keep my mouth shut I did your homework, I can probably knock them out in about 2 hours.
