Question

if 19×10⁵ J of energy is used to raise a 50 kg boy above the ground , then find how high would he be raised ? ( g=9.8m/s²) ​

Answer 1

Given :

Mass of boy = 50 kg

Required energy to raise the boy = 19×10⁵ J

To Find :

Height of boy from the ground.

Solution :

❒ Question is completely based on the concept of potential energy.

• The concept of potential energy applies to only those forces where the work done against the force gets stored up as energy by virtue of position or configuration of the body$.$
• The energy possessed by a body by virtue of its position is called potential energy.

Potential energy of a body of mass m at a height of h from the ground is given by

• U = m × g × h

By substituting the given values;

➙ U = m × g × h

➙ 19 × 10⁵ = 50 × 9.8 × h

➙ 19 × 10⁵ = 490h

➙ h = 19/490 × 10⁵

➙ h = 3.87 × 10³ m = 3.87 km

Answer 2

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$\Large\bold\blue{Given:}$

Mass of boy = 50 kg

Required energy to raise the boy = 19×10⁵ J

$\Large\bold\blue{To\:Find:}$

Height of boy from the ground.

$\Large\bold\blue{Solution:}$

U = m × g × h

Substituting the given values,

U = m × g × h

19 × 10⁵ = 50 × 9.8 × h

19 × 10⁵ = 490h

h = 19/490 × 10⁵

h = 3.87 × 10³ m = 3.87 km