You are the design engineer in charge of the crashworthiness of new automobile models. Cars are tested by smashing them into fixed, massive barriers at 56 km/h (35mph ). A new model of mass 1900 kg takes 0.15 s from the time of impact until it is brought to rest.
1. Calculate the average force exerted on the car by the barrier.
2. Calculate the average deceleration of the car.
To calculate the average force exerted on the car by the barrier, you can use Newton's second law of motion, which states that Force (F) is equal to mass (m) multiplied by acceleration (a).
1. First, let's calculate the acceleration of the car. You can use the formula:
Acceleration (a) = Change in velocity (Δv) / Time taken (Δt)
Given:
Initial velocity (u) = 56 km/h = 56 * (1000 / 3600) m/s (converting from km/h to m/s)
Final velocity (v) = 0 m/s
Time taken (Δt) = 0.15 seconds
Change in velocity (Δv) = v - u
Substituting the given values into the formula:
Acceleration (a) = (0 - (56 * (1000 / 3600))) / 0.15
Once you have calculated the acceleration, you can proceed to the next step.
2. To calculate the average force exerted on the car by the barrier, use the formula:
Force (F) = mass (m) * acceleration (a)
Given:
Mass of the car (m) = 1900 kg
Acceleration (a) = calculated in the previous step
Substituting the given values into the formula:
Force (F) = 1900 kg * calculated acceleration
Once you plug in the values, you can calculate the average force exerted on the car by the barrier.
Now let's move on to the second question:
To calculate the average deceleration of the car, we can use the same formula as before:
Acceleration (a) = Change in velocity (Δv) / Time taken (Δt)
Given:
Change in velocity (Δv) = final velocity (v) - initial velocity (u)
Time taken (Δt) = 0.15 seconds
Substituting the given values into the formula:
Acceleration (a) = (0 - (56 * (1000 / 3600))) / 0.15
Once you have calculated the acceleration, you will have the average deceleration of the car.