If velocity of vehicle doubles in magnitude, what will be its finial kinetic energy. Class 9

If velocity of vehicle doubles in magnitude, what will be its finial kinetic energy. Class 9

Question 1.

If velocity of vehicle doubles in magnitude, what will be its finial kinetic energy be compared to its initial kinetic energy? Class 9

Answer:

Initial kinetic energy of the bullet is K = 1/2 mv²

Final kinetic energy = 1/2 m(2v)² = 4 × 1/2 mv² = 4 K [Final K = 4K].

Question 2.

Cricketer bowled a cricket ball of mass 0.2 kg with velocity of 20 m/s. What is the kinetic energy of ball at the time of its delivery? Class 9

Answer:

K = 1/2 mv² Kinetic energy is K = 1/2 × 0.2 × (20)² = 40 J