please help me?

Question

1. Explain how you can exert a large force on an object without doing any work.
2. Describe how a ramp can make lifting a box easier without changing the amount of work being done.
3. A short ramp and a long ramp both reach a height of 1m. Which one has a greater mechanical advantage?
4. A bus driver applies a force of 55 N of force on the steering wheel which in turn applies 132N of force on the steering column. What is the machanical advantage of the steering wheel?
5.An outboard engine on a boat can do 1 x 10^6 J of work in 50sec. Calculate its power in watts and convert the the answer to horsepower.

Answer 1

1.
Work is defined to be force exerted through a distance. No motion, no work done. No matter *how* much force is exerted.

2.
A ramp makes it appear easier by reducing the amount of force needed. But it also increases the distance traveled, so the work is the same.

3.
The long one, since less force is needed.

4.
132/55 = 2.4 times.

5.
One Watt is defined to be one Joule.second. So
1*10^6/50 = 20,000 Watts. Since 1 hp is defined to be 746 Watts, the engine is putting out
20,000/746 = 26.81 HP.

HTH ☺


Doug