Question

The bob of a simple pendulum is imparted a velocity of 10 ms-1 when it is at its mean position. To what maximum vertical height will it rise on reaching at its extreme position if 40 % of its energy is lost in overcoming the friction of air ? (Take g = 10 ms-2 )​​​​​​​

Answer 1

GIVEN:

• velocity at it's mean position

v= 10 m/s²

• energy lost = 40%

TO FIND:

• maximum height

SOLUTION:

KE at mean position

= 1/2 mv²

=100m/2

=50m

At extreme position 40% energy is lost 60% remains

60/100 × 50 m

0.6× 50 m

30 m

As per law of conservation of energy

PE = KE

m g h = 30 m

h =30/g

h = 3 m

Answer 2

Explanation:

The bob of a simple pendulum is imparted a velocity of 10 ms-1 when it is at its mean position. To what maximum vertical height will it rise on reaching at its extreme position if 40 % of its energy is lost in overcoming the friction of air ? (Take g = 10 ms-2 )