Answer to Question #273128 in Physics for grey tyrant

Question

Problem Solving: Solve the following problems. Show your complete solution and box your final answer.

A farmer attaches her tractor to a sled loaded with sacks of rice to the market. The tractor pulls the sled horizontally to the right with a force of 5000N, 36.9° with the horizontal. The

sled also experiences a frictional force pulling opposite to the direction of the displacement with a force of 3500N. The sled moves to the right with a displacement of 20m over a time period of 10 seconds.

a. Find the work done by the tractor.

b. Find the work done by friction.

c. Find the power of the tractor.

d. Find the power of friction.

Answer 1

a. Find the work done by the tractor:

$$W_a=Fd\cos\theta=5000·20·\cos36.9°=80000\text{ J}.$$

b. Find the work done by friction:

$$W_b=fd=3500·20=70000\text{ J}.$$

c. Find the power of the tractor:

$$P_c=W_a/t=8000\text{ W}.$$

d. Find the power of friction:

$$P_d=W_b/t=7000\text{ W}.$$