calculate the work done to attain a car of velocity 30 m /s having mass 100 kg?
Answers
Answered by
0
force = mass × acceleration = 100 × 30 = 3000N
now, work done in 1 second = force × velocity (distance) = 3000 × 30 = 90000Nm
now, work done in 1 second = force × velocity (distance) = 3000 × 30 = 90000Nm
QGP:
You have applied the wrong concept
Force×Velocity = Power , and not Work
Also, your unit is wrong
It corresponds to Work, not Power (well, that actually had to be the unit of the expected answer)
Answered by
0
Car "attains" a velocity of 30 m/s.
That is, if initial velocity = u
Then final velocity = u + 30
So, we can safely assume u=0
Now, initial Kinetic Energy = 0 ( as u=0)
Final Kinetic Energy K = (1/2)×m×v^2
=(1/2)×100×30
=1500 J
So, ∆K = 1500 - 0 = 1500 J
Now, from Work-Energy Theorem,
W=∆K
So, W=1500 J
Thus, work done is 1500 joules
That is, if initial velocity = u
Then final velocity = u + 30
So, we can safely assume u=0
Now, initial Kinetic Energy = 0 ( as u=0)
Final Kinetic Energy K = (1/2)×m×v^2
=(1/2)×100×30
=1500 J
So, ∆K = 1500 - 0 = 1500 J
Now, from Work-Energy Theorem,
W=∆K
So, W=1500 J
Thus, work done is 1500 joules
Similar questions