1 Answer

Chfw · Answer 1 · 2021-12-01T03:08:06+0000

Given gravitational potential energy when he's lifted is 2058 J.

Kinetic energy is transferred to the person.

Amount of kinetic energy the person has is -2058 J

velocity of person = 7.67 m/s².

Given:

Weight of person = 70 kg

Lifted height = 3 m

1. Gravitational potential energy of a lifted person is equal to the work done.

$PE_g=W=m* g* h\\Acceleration due to gravity = g = 9.8 \ m/s^2 \\PE_g= m = m* g* h= 70* 9.8 * 3 = 2058\ kg.m/s^2 = 2058\ J$

Gravitational potential energy is equal to 2058 Joules.

2. The Gravitational potential energy is converted into kinetic energy. Kinetic energy is being transferred to the person.

3. Kinetic energy gained = Potential energy lost =
$-PE_g = -2058\ kg.m/s^2$

Kinetic energy gained by the person = (-2058 kg.m/s²)

4. Velocity = ?

Kinetic energy magnitude=
(1)/(2) m* v^2 = m* g * h

Solving for v, we get

v=√(2gh) =√(2* 9.8 * 3) = √(58.8) = 7.67 m/s^2

The person will be going at a speed of 7.67 m/s².

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