Jojo, a weight lifter, raises a 150 kg barbell from the floor to a height of 2.2 m in 0.80 s . What is the average power output during the lift.
Jojo lifts a barbell with a mass of 150 kg from the floor to a height of 2.2 m in 0.8 seconds.
The weight of the barbell is 150*9.8 = 1470 N. This is the force that has to be applied to lift the barbell.
The work done when a force of 1470 N is applied over a distance of 2.2 m is 1470*2.2 = 3234 J
As the barbell is lifted from the ground to a height of 2.2 m in 0.8 s, the power exerted is 3234/0.8 = 4042.5 W
Jojo exerts a power of 4042.5 W to lift the 150 kg barbell a height of 2.2 meters in 0.8 seconds.