SAT Subject Physics Practice Question 403: Answer and Explanation

Next steps

Question: 403

9. During a laboratory experiment, a 19.6N pile driver is dropped 2 m on to the head of a nail, which is driven 2.45 cm into a wood board. The frictional force exerted by the wood on the nail is

A. 96.04N
B. 165N
C. 1600N
D. 1960N
E. 3200N

Correct Answer: C

Explanation:

The correct answer is (C). This is a work-energy problem. PE = Work → mgh = F·D. Rearrange, substitute, and solve (remember m·g = wt):

Previous       Next