Question

It is required to increase the velocity of a car of mass 800 kg from 10 m s' to 25 m s' in two seconds. Calculate the force required.​

Answer 1

✯ ᴀɴsᴡᴇʀ ✯

★ given →

☞︎︎︎ ・ mass of car = 800 kg

・ initial velocity of car = 10m/s

・ final velocity of car = 25m/s

_____________________

★ to find →

☞︎︎︎ ・calculate the force required?

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★ solution →

☞︎︎︎ we know that,

force acting on an object is equal to change in momentum

• F = force
• M = momentum
• v = final velocity
• u = initial velocity
• m = mass

and we also know that,

momentum is equal or product of mass and velocity of an object

➪ M = mv

・initial momentum = mu

・final momentum = mv

✩ force = change in momentum

➪ F = mv - mu

➪ F = (800 × 25) - (800 × 10)

➪ F = 800(25 - 10)

➪ F = 800 × 15

➪ F = 12000

hence, force required is 12000 Newton.

Answer 2

Explanation:

Force is required to change the velocity of any body (here scooter). As we know according to newton’s second law of motion : F= ma .

Here we are given with initial and final velocities and the time interval required for the change. We can calculate acceleration as :

acceleration=change in velocity/time

Change in velocity= final velocity - initial velocity

So acceleration = 25–5/2 =20/2 = 10m/sec^2

So force required = mass of scooter*acceleration = 80*10 = 800N

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