Question

A mass of 35 kg dropped from a height of 10m .Find it's (i)velocity and (ii) Kinetic energy as it just reaches the ground .take g=9.8 m/s^2

Answer 1

Height = 10 m

Initial velocity (u) = 0

Final velocity = v

acceleration due to gravity = 9.8 m/s^2

$v^2 = u^2 +2ah$

$v=\sqrt{2\times 9.8 \times 10}$

v = 14 m/s

Hence, the velocity at the bottom is 14 m/s

Now, kinetic energy formula is:

$K.E. = \frac{1}{2}\times m \times v^2$

$K.E. = \frac{1}{2}\times 35 \times 14 \time 14$

Kinetic energy = 3430 Joules

Hence, the kinetic energy is 3430 J

Answer 2

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