Question

A rocket of mass 15000 kg accelerates at 22 −1
for 30 s from an initial speed of 550 /. What will be final kinetic energy of the rocket?​

Answer 1

Given:-

• Mass of rocket = 15000kg

• Acceleration (a) = 22m/s²

• Time taken (t) = 30s

• Initial velocity (u) = 550m/s

To Find:-

• Final Kinetic Energy of the rocket (K)

Solution:-

As we know that the energy possess by body due to its motion is called Kinetic Energy

Firstly we have to finad the final velocity of the rocket. So by using 1st equation of motion

→ v = u+at

Substitute the value we get

→ v = 550+22×30

→ v = 550 + 660

→ v = 1210m/s

Now, Kinetic Energy

→ K = 1/2mv²

Substitute the value we get

→ K = 1/2×15000×(1210)²

→ K = 7500 × 1464100

→ K = 10980750000 J

→ K = 10980750000/1000 = 10980750 kj

∴ The kinetic energy of the rocket is 10980750 kilo Joule.

Answer 2

Given :-

• Mass (m) = 15000kg
• Acceleration (a) = 22m/s²
• Time (t) = 30s
• Initial velocity (u) = 550m/s

To Find :-

• The kinetic energy of the rocket.

Solution :-

☀ Finding Final velocity of rocket. ☀

Applying 1st equation of motion,

↪ v = u + at

↪v = 550 + 22 × 30

↪ v = 550 + 660

↪v = 1210m/s.

.°. Final Velocity (v) = 1210m/s.

☀ Now Finding kinetic energy of the rocket. ☀

We know that,

↪K.E = 1/2 mv²

↪K.E = 1/2 × 15000 × (1210)²

↪K.E = 7500 × 1464100

↪K.E = 10980750000J.

Hence,

• The kinetic energy of the rocket is 10980750000J.