## TheSmartOne one year ago If a car's mass is 600 kg, and its speed is 10 m/s. And a scooter's mass is 80 kg, and the scooter's speed is 50 m/s. Then which will require more force to stop it if the distance is the same?

1. TheSmartOne

@Michele_Laino :)

2. TheSmartOne

I thought we used f = ma And then f = 600 x 10 f = 6,000 And f = 80 x 50 f = 4,000 So it would take more force to stop the car. Am I correct? :P

3. Michele_Laino

the object which requires more force is the object which has the highest kinetic energy

4. Michele_Laino

now the kinetic energy of the car is: 0.5 * 600*100=30,000 Joules whereas kinetic energy of scooter is: 0.5*80*2500=100,000 Joules

5. Michele_Laino

so it is the scooter

6. Michele_Laino

oops.. formula for kinetic energy is: $$KE=1/2 \cdot m \cdot v^2$$

7. TheSmartOne

oh thank you so much :D

8. TheSmartOne