MEDAL GIVEN TO CORRECT ANSWER.
Tory has a mass of 40 kg. She sleds down a hill that has a slope of 25°. What is the component of her weight that is along her direction of motion?

A. 355 N
B. 198 N
C. 166 N
D. 392 N

Question

MEDAL GIVEN TO CORRECT ANSWER. 
Tory has a mass of 40 kg. She sleds down a hill that has a slope of 25°. What is the component of her weight that is along her direction of motion?

 		A.	355 N
 		B.	198 N
 		C.	166 N
 		D.	392 N

anonymous · Answer

If you draw a free body diagram, the normal force should be pointing up, and mgcos(theta) should be straight down. In the direction of her motion is the component mgsin(theta), which in this case is: 40*9.8*sin(25)= 165.6 N which rounds to 166 N. The correct answer is C.