Physics, asked by yash6714, 1 year ago

8. A car weighing 1000 kg travelling along a level
road is accelerated for 2 min at the rate of
15 m st. Find its gain of kinetic energy during
those 2 min.
[Ans. 1.62 x 10' J]​

Answers

Answered by adityapatil12102003
24

Explanation:

Given,

m=1000 kga=15m/s

2t=2minutes=2×60=120 su=0Using

relation,

v=u+at=0+15×120=1800 m/s

Gain in kinetic energy=12mv2−12mu2

=12×1000(18002−0)

=1620000000 J=1620000kJ

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Answered by dualadmire
1

The gain in kinetic energy during that 2 min is 1.62 × 10^8 J.

Given: A car weighing 1000 kg traveling along a level road is accelerated for 2 min at the rate of 15 m/s².

To Find: The gain of kinetic energy during that 2 min.

Solution:

  • We need to first use the formula to find the final velocity of the car.

                  v = u + at                                                                      .....(1)

Where v = final velocity, u = initial velocity, a = acceleration, t = time.

  • It is to be assumed that the car started from rest and hence initial velocity is equal to zero.
  • The gain in kinetic energy of the car can be calculated using the formula,

             Δ K.E = 1/2 × m × ( v² - u² )                                           ....(2)

Where m = mass of the car, v = final velocity, u = initial velocity.

Coming to the numerical, we are given that;

The mass of the car = 1000 kg

The acceleration of the car = 15 m/s²

The time = 2 min = ( 2 × 60 ) s

               = 120 s

The initial velocity (u) = 0

Putting respective values in (1), we get;

           v = u + at        

       ⇒  v = 0 + ( 15 × 120 )

       ⇒  v = 1800 m/s

Now, putting the respective values in (2), we get;

           Δ K.E = 1/2 × m × ( v² - u² )    

        ⇒ Δ K.E = 1/2 × 1000 × (( 1800 )²  -  0² )

        ⇒ Δ K.E = 1/2 × 324000000

        ⇒ Δ K.E = 162000000 J

                       = 1.62 × 10^8 J

Hence, the gain in kinetic energy during that 2 min is 1.62 × 10^8 J.

#SPJ2

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