Question

A man is travelling in a bus with velocity of 60m/s and his weight is 70 kg .what is the kinetic energy of a man?​

Answer 1

Answer:

Kinetic energy is 126000J or 126kJ.

Step-by-step explanation:

Given:-

• A man is travelling in a bus with velocity of 60m/s.
• Weight of the mas is 70 kg.

To Find:-

Kinetic energy of the man.

Solution:-

If an object is moving then it has energy, that energy maybe in the form of Kinetic energy and Potential energy.

Kinetic energy is that energy which is possessed by an object due to virtue of it's motion. Whereas, Potential energy is that energy which is possessed by an object due to virtue of it's shape or position.

Since, the man is in motion. Means we are talking about his Kinetic energy.

$\sf{\huge{K.E.=1/2mv^2}}$

(K.E. = Kinetic Energy)

Here-

• m = mass in kg
• v = velocity in m/s
• K.E. = kinetic energy in J.

From the above data we have; v = 60 m/s and m = 70 kg.

Substitute the known in the above formula,

$\implies\:\sf{K.E.=1/2 \times 70 \times (60)^2}$

$\implies\:\sf{K.E.=70/2 \times 3600}$

$\implies\:\sf{K.E.=35 \times 3600}$

$\implies\:\sf{K.E.=126000J}$

To convert J into kJ. Divide the given value by 1000.

So,

$\implies\:\sf{K.E.=126000/1000}$

$\implies\:\sf{K.E.=126kJ}$

Therefore, the kinetic energy of a man is 126kJ or 126000J.

Answer 2

AnswEr :

Given that a man is travelling in a bus with a velocity of 60 m/s and his weight is 70 kg.

We have to find kinetic energy of that man.

From the above conditions we have :-

➡ Velocity (v) = 60 m/s

➡ Mass (M) = 70 kg

As we know the formula for finding kinetic energy :-

→ Kinetic energy (K.E.) = ½ mv²

In that formula :-

• m : mass of object
• v : velocity of object

Substituting values,

→ K.E. = ½ × 70 × (60)²

→ K.E. = 35 × 3600

→ K.E. = 126,000 J

→ K.E. = (126,000/1000) kj

→ K.E. = 126 kj

∴ Kinetic energy of man is 126,000 J or, 126 kj  ‎ ‎ ‎ ‎ ‎ ‎(Answer)

______________________

● One more formula related to energy :-

→ Potential energy (P.E. ) = m × g × h

In that formula :-

• m : mass of object
• g : gravitational acceleration
• h : height.