Question

using intergrals a car braked with a constant deceleration of 8 ft/s2, producing skid marks measuring 100 ft before coming to a stop. how fast (in ft/s) was the car traveling when the brakes were first applied?

Answer 1

The car was traveling at a speed of 40 ft/s when the brakes were first applied.

Step-by-step explanation:

To find the initial speed of the car when the brakes were first applied, we can use the kinematic equation:

v2 = u2 + 2as

where v is the final velocity (0 ft/s), u is the initial velocity (unknown), a is the deceleration (-8 ft/s2), and s is the distance traveled (100 ft).

Plugging in the values, we get:

0 = u2 + 2(-8)(100)

Simplifying, we have:

u2 = 1600

Taking the square root of both sides, we find:

u = 40 ft/s

Therefore, the car was traveling at a speed of 40 ft/s when the brakes were first applied.