Have 2 identical cars each 1000kg at a speed of 20m/s. The yellow car is stopped by car's brakes in 25m while green car is stopped by concrete barrier in 1.2m. Drivers have same mass(70kg) Driver of yellow car is stopped by seatbelt in 0.150 sec.
Compare impulse they received in stopping. Would that be 70 * (0-20)for yellow car
Green car it would be 70 * (0-20)
How do I calculate average force exerted on each driver? I'm really stuck
To calculate the average force exerted on each driver, you need to use the principle of impulse. Impulse is the change in momentum, and it can be calculated using the formula:
Impulse = Force × Time
First, calculate the impulse for the yellow car's driver. We know the mass of the driver is 70 kg and the time it took to stop was 0.150 seconds. The initial momentum of the driver can be calculated as the product of the mass and the initial velocity (20 m/s):
Initial momentum = mass × initial velocity
= 70 kg × 20 m/s
Next, calculate the final momentum, which is zero since the driver comes to a stop:
Final momentum = 0 kg × 0 m/s
= 0 kg·m/s
The change in momentum is the difference between the initial and final momentum:
Change in momentum = Final momentum - Initial momentum
= 0 kg·m/s - (70 kg × 20 m/s)
Now, divide the change in momentum by the time taken to stop to get the average force exerted on the driver:
Average force = Change in momentum / Time
= (0 kg·m/s - (70 kg × 20 m/s)) / 0.150 s
Follow the same steps to calculate the average force for the driver of the green car, except use the corresponding values for mass, time, and change in momentum.
By comparing the average forces exerted on each driver, you can determine which driver experienced a greater force during deceleration.