How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?
A) 0.22 kJ
B) 0.20 kJ
C) 0.24 kJ
D) 0.27 kJ
E) 0.31 kJ

Question

Quizplus · Accepted Answer

The work done is calculated using the formula Work = Force x Distance. Since the object is lifted at a constant speed, the force exerted equals the weight of the object (mass x gravity). Here, gravity (g) is 9.8 m/s^2. So, Force = 2.0 kg x 9.8 m/s^2 = 19.6 N. The distance (d) the object is lifted can be found by multiplying the speed (2.0 m/s) by the time (5.0 s), giving d = 10.0 m. Therefore, Work = 19.6 N x 10.0 m = 196 Joules or 0.196 kJ, which rounds to 0.20 kJ.

How Much Work Is Done by a Person Lifting a 2.0-Kg