A car mass of 900kg travelling at 15m/s crashes into a wall and comes to rest in 0.3s. Calculate the average decelaration. Calculate the average force exerted
a. V = Vo + a*t.
V = 0, Vo = 15 m/s, t = 0.3 s., a = ?. a will be negative.
b. F = M*a. F will be negative.
To calculate the average deceleration, we can use the formula:
Average deceleration = (final velocity - initial velocity) / time
Given that the initial velocity (v0) is 15 m/s, the final velocity (v) is 0 m/s, and the time (t) is 0.3 s, we can substitute these values into the formula:
Average deceleration = (0 - 15) / 0.3
Average deceleration = -15 / 0.3
Average deceleration = -50 m/s^2
The average deceleration is -50 m/s^2, indicating that the car is accelerating in the opposite direction, which is called deceleration.
To calculate the average force exerted, we can use Newton's second law of motion:
Force = mass * acceleration
Given that the mass (m) of the car is 900 kg and the average deceleration (a) is -50 m/s^2, we can substitute these values into the formula:
Force = 900 kg * (-50 m/s^2)
Force = -45,000 N
The average force exerted on the car is -45,000 Newtons.
To calculate the average deceleration, we can use the formula:
Average deceleration (a) = (final velocity - initial velocity) / time
In this case, the initial velocity is 15 m/s (the car's speed before the crash), the final velocity is 0 m/s (since the car comes to rest), and the time is 0.3 seconds.
Substituting these values into the formula:
a = (0 - 15) m/s / 0.3 s
To simplify, we can convert the units:
a = (-15 m/s) / (0.3 s)
a = -50 m/s^2
The negative sign indicates that the car is decelerating (or accelerating in the opposite direction).
Now, to calculate the average force exerted, we can use Newton's second law of motion:
Force (F) = mass (m) x acceleration (a)
Given that the car's mass is 900 kg, and the average deceleration is -50 m/s^2 (negative because it's deceleration):
F = 900 kg x (-50 m/s^2)
F = -45,000 N
Again, the negative sign indicates that the force is in the opposite direction of the initial velocity.