Answered

An automobile engineer found that the impact of a truck colliding at 16 km/h with a concrete pillar caused the bumper to indent only 6.2 cm. The truck stopped. Determine the acceleration of the truck during the collision.

Answer :

Edufirst
An important assumption to solve this problem is that the acceleration is uniform (constant).

Under that assumption you can use following formulae.

Acceleration = [Final velocity - Initial velocity] / time

You have final velocity = 0 and initial velocity = 16 km/h

Then you need to find the time.

Average velocity = [distance / time]

In this case the distance is the deformation of the bumper: 6.2 cm = 0.062 m = 0.000062 km

And when acceleration is constant, the average speed is equal to [Initial velocity + Final velocity] / 2 = [16 km/h + 0] /2 = 8 km/h

Now you can calculate time solving from Average velocity = [distance / time]

time = distance / average velocity =  0.000062 km / 8 km/h = 0.00000775 h

And, finally we can use the formula Acceleration = [Final velocity - Initial velocity] / time

Acceleration = [16 km/h - 0 km/h] / 0.00000775 h = 2,064,516 km/h^2




Other Questions