Question

What is the work to be done
to increase the velocity of a car from
30 km h^-1 to 60 km h if the mass of
the car is 1500 kg?​

Answer 1

Answer:

E=K=1/2m(v-u)²

Apply the formula and solve your question...

Please make sure that you convert the given speed from km/h to m/s...You will get your answer in joule...

Answer 2

Answer :

The work done = 156250 J

Explanation :

Mass of the car, ( m ) = 1500 kg

Initial velocity of car ( u ) = $30\:km\:h^{-1}$

→ $30 × 1000\:m / 60 × 60\:s$

→ $25 / 3\:m\:s^{-1}$

Similarly, the initial velocity of the car,

$v = 60\:km\:h^{-1}$

= $50 / 3</strong><strong>\</strong><strong>:</strong><strong>m\:s^{-1}$

So, Initial kinetic energy of the car,

$E\:{ki} = 1 / 2\:m\:u^{2}$

= $1 / 2 × 1500\:kg × ( 25 / 3\: m\:s^{-1} )^{2}$

= $156250 / 3\:J$

The final kinetic energy of the car,

$E\:{kf} = 1 / 2 × 1500\:kg × ( 50 / 3\:m\:s^{-1} )^{2}$

= $625000 / 3\:J$

Thus, the work done = change in kinetic energy

=> $E\:{kf} - E\:{ki}$

=> $( 625000 / 3 )\:-\:( 156250 / 3 )$

=> $156250\:J$

♥ So, It's Done ♥ !!