Question

Question:
What force is required to bring a 900 kg car to rest from speed 120 km/h within a distance of 50 m? ​

Answer 1

Answer:

Answer is Force of friction is required.

Explanation:

friction opposess the car from the speed with the tyres of car.

what I know I shared with you.

I hope it helps you

Thank you...

Answer 2

Explanation:

GIVEN:

m = 900 kg

x = 50 m

Vf = 0

Vo = 120 km/hr × 1000m/1km × 1hr/3600 s

>cancel the unit km & hr

Vo = (100/3) m/s

REQUIRED:

F = ?

SOLUTION:

F = mass × acceleration

Acceleration is not given so you have to solve for its value with respect to the given values, the nearest formula to use is:

a = (Vf² - Vo²)/2x

a = ( (0m/s)² - (100/3 m/s)²) / (2 × 50 m)

a = (-10000/9 m²/s²) / (100 m)

>cancel unit m

a = -100/9 m/s²

Negative acceleration means that the body is deccelerating or it is losing its speed in my words. We can now plug in the value of acceleration to the formula:

F = ma

F = (900 kg)(-100/9 m/s²)

F = -10000 kg m/s²

Negative Force is an indication that the Force is acting on the opposite of the motion, which is correct in this type of problem.

But it is safe to say that the force required to bring a 900 kg car to rest from speed 120 km/h within a distance of 50 m is 10000 kg m/s².