Question

Q:15 To lift a body through 10 m upwards, energy of 9800 J is
required. The mass of the body is (g=10ms-2)​

Answer 1

Gɪᴠᴇɴ :-

• Height (h) = 10 m
• Potential Energy (PE) = 9800 J
• Acceleration due to gravity (g) = 10 m/s²

ᴛᴏ ғɪɴᴅ :-

• Mass (m) of the body

sᴏʟᴜᴛɪᴏɴ :-

We know that,

➦ Potential Energy = Mass × Acceleration × Height

➦ PE = m × g × h

➭ 9800 = m × 10 × 10

➭ 9800 = 100m

➭ m = 9800/100

➭ m = 98 kg

Hence,

• Mass of the body is 98 kg

Answer 2

$\sf{\underline{Answer\::}}$

A body of mass 98 kg can be lifted to a height of 10 m with enery of 9800 J.

$\sf{\underline{Explanation\::}}$

It is said that a body is to be lifted 10 m upwards and energy required in doing so is 9800 J. We have to find what is the mass (m) of the body.

We know,when a body is lifted certain amount of work is done and when the work is done in lifting a body the energy we are dealing here will be potential energy (gravitational).

We know the formula of PE,

$\bold{Potential\:Energy_{(E_p)}=\:mgh}$

Where,

• m = mass of the body
• g = acceleration due to gravity
• h = height

Use these data & plug them in the formula and you can find the unknown quantity.

=> $\sf{9800\:=\:m\:\times\:10\:\times\:10}$

=> $\sf{9800\:=\:m\:\times\:100}$

=> $\sf{9800\:=100m}$

=> $\sf{\dfrac{9800}{100}\:=m}$

=> $\sf{m=98}$

•°• Mass of the body is 98 kg.