Question

(a) Name two forms of mechanical energy. Define one the SI unit of energy.
(b) A man of mass 50kg jumps from a height of 0.5m here if gany=10 ms-2 what will be his energy at the highest point.
(c) Calculate the energy of body of mass 20kg moving the velocity of 0.1m/s

Answer 1

potential and kinetic energy
the SI unit of work or energy, equal to thework done by a force of one newton.

i calculate its kinetic energy in (b
b: M = 20 kg

v = 0.1 m/s

kinetic energy = 1/2 × m × v^2 

= 1/2 × 20 × ( 0.1 )^2 

= 10 × 0.01

= 0.1

so kinetic energy is 0.1 J

Answer 2

Hey!

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Here are the answers-:

a) Mechanical energy is of two types -

• Kinetic energy
• Potential energy

Kinetic energy is the energy possessed by a body because of virtue of its motion.

Formula to find kinetic energy is 1/2 mv^2
Where, m = mass and v= velocity.

SI unit of energy is = joules (J)

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b) Mass = 50 kg
Height = 0.5 m
Gravity due to Acceleration = 10 m/s^2
Energy at highest point =?

Potential energy = mgh
P.E = 50×10×0.5
P.E= 500×0.5
P.E= 250 J

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c) Mass = 20 kg
Velocity = 0.1 m/s
Kinetic energy = ?

K.E = 1/2 mv^2
K.E = 1/2 × 20 × 0.1 × 0.1
K.E = 0.1 J

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Hope it helps...!!!