Question

A weight-lifting athlete raises a mass of 160 kg through a vertical distance of 1.4 m. What force did

he apply to the mass to lift it and how much energy did he use for that lift?

Answer 1

1568N

2195.2J

Step-by-step explanation:

Given parameters:

Mass of the weight = 160kg

Distance = 1.4m

Unknown:

Force applied to lift the weight = ?

Energy expended = ?

Solution:

The force applied in moving a body with a given mass through a distance is the weight;

Force applied = mg

Where m is the mass

g is the acceleration due to gravity

i. Applied force = 160 x 9.8 = 1568N

ii. The energy used to lift the weight is given as;

Energy = mgh

h is the vertical distance

Energy = 1568 x 1.4 = 2195.2J