What is the work to be done to increase the velocity of a car from 30km per hr to 60km per hr, if the mass of a car is 1500 kg
Answers
v =60km = 60000/3600=16.6 m/s
u = 30km =30000/3600=8.3 m/s
mass=1500kg
work done= change in kinetic energy
w=1/2mv2_1/2 mu2
w=1/2*1500*16.6-1/2 *1500*8.3
W=12450j - 6225j
W=6225j
W=6.225*103
joule
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.