A body of mass 5kg falls from a height of 10m above the ground.what is the kinetic energy of the body just before it hits the ground.[g=10ms-2
500 J
what is mgh?
12331
To find the kinetic energy of the body just before it hits the ground, we need to use the formula for kinetic energy.
The formula for kinetic energy is given by:
Kinetic Energy = 1/2 * mass * velocity^2
To find the velocity, we can use the equations of motion.
We know that the body is falling freely under the influence of gravity, so we can use the equation:
final velocity^2 = initial velocity^2 + 2 * acceleration * distance
Given:
Mass (m) = 5 kg
Height (h) = 10 m
Acceleration due to gravity (g) = 10 m/s^2
Using the equation of motion, we can find the final velocity:
0 = initial velocity^2 + 2 * g * h
initial velocity^2 = -2 * g * h
initial velocity = sqrt(-2 * g * h)
Since the body is falling vertically downwards, we take the positive square root.
initial velocity = sqrt(2 * g * h)
Now, we can substitute the values into the kinetic energy formula to find the answer:
Kinetic Energy = 1/2 * mass * velocity^2
= 1/2 * 5 kg * (sqrt(2 * 10 m/s^2 * 10 m))^2
= 1/2 * 5 kg * (sqrt(200))^2
= 1/2 * 5 kg * 14.142 m/s * 14.142 m/s
= 1/2 * 5 kg * 200 m^2/s^2
= 500 J
Therefore, the kinetic energy of the body just before it hits the ground is 500 Joules.