Question

A truck traveling at 80 mph runs into a bridge abutment and crumples for 0.8 m before coming to a full stop. If we estimate the process as constant deceleration motion, what is the average force exerted on the car, with mass 3500 kg, during the collision process

Answer 1

U = 80mph = 35.76m/s

S = 0.8m

M = 3500kg

To find the deceleration, we use equation of motion to calculate that

V² = u² + 2as

But v = 0

0 = u² + 2as

-U² = 2as

a = -u² / 2s

a = -(35.76)² / (2 * 0.8)

a = 1278.78 / 1.6 = 799.24 m/s²

The force exerted on the truck during deceleration is equal to the summation of all the forces acting on the truck.

∑F = m. ⃗a

-F = 3500 * 799.24

F = -2797331.25N

F = -2797.33kN

F = -2.797MN.