- #1

Caldus

- 106

- 0

Here are some problems that I'm having trouble with on this review worksheet I was given. I don't need answers, I need to know how to do these problems. If anyone could show me how to do at least a problem or two then I would greatly appreciate it:

1. A pilot heads due north at an air speed of 380 km/h. A 112 km/h wind is blowing from the west. Calculate the velocity of the plane relative to the ground. (I just don't know how to convert from km/h to m/s.)

2. An object is shot up into the air at a 45 degree angle with a velocity of 141 m/s. Calculate the distance the object travels before striking the ground.

3. An astronaut weighs 900 N at the Earth's surface. Calculate the astronaut's weight at an altitude of 32,000 km above the Earth's surface.

4. A 5.0 g bullet leaves a gun at 1.00 x 10^3 m/s. The gun has a mass of 4.0 kg. Calculate the recoil velocity of the gun.

5. A 2.85 x 10^5 N freight car coasts along a level track at 1.2 m/s. The brakes are applied, and the car stops in a distance of 6.0 m. Calculate the average braking force.

6. What is the kinetic energy of a 15,700 N car moving at 30 km/h?

7. A 6.0 kg ball is at rest at the top of an inclined plane that is 2.5 m tall. What is the speed of the ball when it reaches the bottom of the incline?

8. A track star in the broad jump goes into the jump at 12.0 m/s and launches himself at 20.0 degrees above the horizontal. How far does he jump?

9. An object that weighs 5000 N is suspended by two cables. Cable 1 applies a horizontal force to the right of the object and has a tension T1. Cable 2 applies a force upward and to the left at an angle of 37 degrees with the horizontal and has a tension T2. Determine the magnitude of T1 and T2.

10. Determine the acceleration of a 25 kg crate that is pulled across the floor by a 275 N force applied at 35 degrees above the horizontal. The frictional force is 15 N.

11. What upward force is applied by a crane to lift a 2200 kg car at a constant velocity of 5 m/s.

12. What upward force is applied by a crane to lift a 2200 kg car at a constant upward acceleration of 5.0 m/s^2?

Again, I'm not looking for someone to do all of these, but at least a few maybe so that I may be able to figure out other problems.

Thanks.