Calculate the work required to be done to stop a car of 250 kg moving at a speed of 18km/hr?
answer is right or not please check
Mass =250 kg
Velocity = 18kg = 18 x 1000/60 x 60 = 5 m/s
KE = ½ mv x v = ½ x 250 x 5 = 125 x 5 = 625 J
Therefore the counter back this force we need the equal and opposite force.
Therefore Work needed = 625 J
(1/2) m v^2 = (1/2)(250) * 25
because 5^2 = 25
= 3125 Joules
To calculate the work required to stop a car, we need to find the kinetic energy (KE) of the car first. The formula for kinetic energy is KE = 1/2 * mass * velocity^2.
Given:
Mass (m) = 250 kg
Velocity (v) = 18 km/hr
To convert velocity from km/hr to m/s, we divide it by 3.6 since 1 km/hr = 1 m/s. Thus, the velocity in m/s is:
18 km/hr = 18 * (1000/3600) = 5 m/s.
Now we can calculate the kinetic energy:
KE = 1/2 * mass * velocity^2
KE = 1/2 * 250 * 5^2
KE = 1/2 * 250 * 25
KE = 625 J (Joules)
Therefore, the work needed to stop the car would be equal to the kinetic energy, which is 625 Joules.