1. How much work is done when a weight lifter holds a 5KG barbell over his head at a height of 10m for 50s?
Givens:
m = 5KG
d = 10m
t = 50s
Where m is mass, d is distance, and t is time.
The formula for work is W = FD; W is work, F is force, and D is distance.
2007-10-10 13:40:17 · 1 answers · asked by killerwu753 1 in Science & Mathematics ➔ Physics
For the next question...
What is the velocity of a ball if it has a kinetic energy of 500J and a mass of 10KG?
2007-10-10 14:02:46 · update #1
Use the formula W = F*d
This equation works for a constant force in the direction of movement (or in the opposite direction). The d in this equation represents how far the object moves while the force is applied. .
When the weightlifter holds the barbell over his head, it isn't moving. d = 0. Therefore work is zero.
2007-10-10 13:53:06 · answer #1 · answered by Demiurge42 7 · 0⤊ 0⤋