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 51 km/h (32 mph). A new model of mass 1900 kg takes 0.18 s from the time of impact until it is brought to rest.
Calculate the average force exerted on the car by the barrier.
Calculate the average deceleration of the car.
force*time= mass*changevelocity
solve for force.
force= m*a solve for a
that doesn't work (at least that's what our teacher is telling is)
If you lift a 57.7kg box 2.41m over your head, how much work did you do?
Read your Notes jeje.. Hope this helps :)
To calculate the average force exerted on the car by the barrier, we can use Newton's second law of motion, which states that the force applied to an object is equal to the object's mass multiplied by its acceleration.
First, let's calculate the acceleration of the car using the time and the initial velocity. We know that the initial velocity is 51 km/h (32 mph) and we need to convert it to m/s. There are 3.6 m/s in 1 km/h, so the initial velocity is 51 km/h * (3.6 m/s / 1 km/h) = 183.6 m/s.
Next, we can use the formula of average acceleration: acceleration = change in velocity / time. The final velocity is 0 m/s because the car is brought to rest. Therefore, the change in velocity is 0 - 183.6 m/s = -183.6 m/s (negative sign indicates deceleration).
Now we can calculate the average deceleration of the car. Average deceleration = change in velocity / time = (-183.6 m/s) / 0.18 s = -1020 m/s².
Finally, we can calculate the average force exerted on the car using Newton's second law. Force = mass * acceleration = 1900 kg * (-1020 m/s²) = -1938000 N.
The force exerted on the car by the barrier is approximately -1,938,000 Newtons (N). Note that the negative sign indicates that the force is in the opposite direction to the motion of the car, as it is a deceleration force.