The velocity of a car increases from 90km/hr to 108 km/hr. How much is the work done if the mass of the car is 2000 kg?
Answers
Answered by
1
Answer:
Correct option is
B
131250J
Initial Velocity, u=54km/hr=15m/s
Final velocity , v=72km/hr=20m/s
Mass =1500kg
Initial kinetic energy 21mu2
⇒211500×15×15=168750J
Final kinetic energy 21mv2
⇒211500×20×20=300000J
So, change in kinetic energy = work done=300000−168750=131250J
Explanation:
I think it helps you
Answered by
0
Answer:
275000J
Explanation:
Given:
- initial velocity u = 90km/h = 25m/s
- final velocity v = 108km/h = 30m/s
- mass m = 2000kg
Solution:
initial kinetic energy = 1/2×m×u^2 =1/2×2000×25×25=625000J
final kinetic energy = 1/2×m×v^2 =1/2×2000×30×30=900000J
work done = change in Kinetic energy = final
- initial
= 900000 - 625000 = 275000J
Note:
shortcut to convert km/h to m/s is multiply by 5/18
90×5/18 = 25
108×5/18 = 30
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