Question

)
What is the work needed to be done to increase the velocity of a car from 30
Kmh-1 to 60 Kmh-1 if the mass of the car is 1500 Kg.
notential energies of an object is called its​

Answer 1

Answer:

156250J

Explanation:

So in this Question the car is already on motion, so it posses energy due to motion or kinetic energy

We know that, here they are asking about the work done but energy is work done

Let's prove it fast

W = F × s

F = m × a

so, W = m × a × s

we know from, third equation of motion that

v² - u² = 2as

so, as = (v² - u²)/2

so, W = m(v² - u²)/2

When the initial velocity is 0, u = 0

so, K.E. = (1/2) × m × v² = (1/2)mv²

so we came to know that work done is energy

Here kinetic energy is changing so

K.E. = (1/2)m(v² - u²)

where m = 1500kg

u = 30km/h × (5/18) = 25/3 m/s

v = 60km/h × (5/18) = 50/3 m/s

(We know that to convert from km/h to m/s we need to multiply by 5/18)

K.E = (1/2) × 1500 × ( (50/3)² - (25/3)²)

= 750 × ((2500/9) - (625/9))

= 750 × (1875/9) = 1406250/9 = 156250J

Therefore, it takes 156250J of work to increase the velocity of a car from 30Kmh-1 to 60 Kmh-1 if the mass of the car is 1500 Kg.

Hope you understood it........All the best

Answer 2

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.