Question

A mover hoists a 200 kg piano from the ground to a height of 10 m using a single pulley. What was the change in the piano's energy?

A. 20 J
B. 200 J
C. 2,000 J
D. 20,000 J

Answer 1

@Michele_Laino :)

Answer 2

the requested potential energy change is equal to the work done by mover hoists

Answer 3

W=F X displacement

Answer 4

so our solution is 200 J ? choice B?

Answer 5

W = 200 X 10

Answer 6

oh! so 2000, choice C is our solution?

Answer 7

no, since 200 Kg is the mass of the piano. The work is:
\[\Large W = 200 \times 9.81 \times 10 = ...Joules\]

Answer 8

yep need to convert

Answer 9

oh so we get 19620? so choice D, 20,000 J is our solution?

Answer 10

correct!

Answer 11

yep

Answer 12

yay!! thank you both!!

Answer 13

:)