What is the work to be done to increase the velocity of car from 30 km/h to 60 km/h if the mass of the car is 1500 kilogram (kg) ?
Answers
Work = Change in kinetic energy
= 0.5 m (v² - u²)
= 0.5 × 1500 kg × [(60 × 5/18 m/s)² - (30 × 5/18 m/s)²]
= 156250 joules
= 156.25 kJ
Or
Mass of the car,m= 1500kg
Initial velocity of the car = 30km/hr
= 30×1000m/60 ×60s
=8.33m/s
Similarly,the final velocity of the car,
v= 60km/hr
=16.67 m/s
Therefore,the initial kinetic energy of the car,
E(initial) = 1/2 mu^2
=1/2×1500×8.33
52041.68 J.
The final kinetic energy of the car,
E(final) = 1/2 1500×16.67
=208416.68 J.
Thus, the work done = change in kinetic energy
= E(final) - E(initial)
= 208416.68 - 52041.68
= 156375 J.
Answer:
Work done is 156250 J.
Explanation:
Given,
The mass (m) of the car is 1500 kg.
Initial velocity of car = u = 30 km / hr = 30 * 5/18 = 25 / 3 m/s
Final velocity of car = v = 60 km / hr = 60 * 5/18 = 50/3 m/s
To find: The work to be done to increase the velocity of a car from
30 km h-1 to 60 km h^-1
Solution:
Initial kinetic energy = Ki = 1/2mu² = 1/2*1500*25/3 * 25/3 = 156250/3 J
Final Kinetic energy = Kf = 1/2mv² = 1/2*1500*50/3*50/3 = 625000/3 J
Work done can be given as change in Kinetic Energy,
i.e W = ΔK.E
or, W = Kf - Ki
or, W = 625000/3 - 156250/3
or, W = 156250 J
Therefore, Work done is 156250 J.