A 2.77 kg book is lying on a 0.722 m high table. You pick it up and place it on a bookshelf 2.28 m above the floor. How much work does gravity do on the book?
2007-02-20 08:44:19 · 3 answers · asked by N 1 in Science & Mathematics ➔ Physics
W = m*g*Dh = 2.77 *9.8 *(2.28-0,722) =42.3935 joules
2007-02-20 08:51:48 · answer #1 · answered by santmann2002 7 · 0⤊ 1⤋
W = Fx
the mass is not a force, weight is. So we have to find the weight
W = mg
W = 2.77 * 9.8
W = 27.146
since the book is alreay at .722m, you pick it up at 2.88m above the floor, that means you only lift the book 2.88 - .722m = 2.108m
W = 27.146N * 2.108m
W = 57.223J
2007-02-20 17:06:29 · answer #2 · answered by 7 · 0⤊ 0⤋
F=mg therefore, F= (2.77)(9.8) which equals 27.146
Wg = -mgh
Wg= -mgh
Wg= (2.77)(9.8)(.722)
Wg= 19.5994 is your answer
2007-02-20 16:57:01 · answer #3 · answered by jenibaby01 1 · 0⤊ 1⤋