Question

A car slows down from 35 m/s to rest at a distance of 140 m. What is its acceleration, assumed constant? If your answer is negative, do not forget to include a negative sign.

Answer 1

The constant acceleration of the car as it slows down from 35 m/s to rest over 140 m is -4.375 m/s^2, with the negative sign indicating deceleration.

Step-by-step explanation:

The question asks about finding the acceleration of a car slowing down from 35 m/s to rest over a distance of 140 m. To find the acceleration, we can use the kinematic equation:

\(v^2 = u^2 + 2as\)

Where:

v = final velocity (0 m/s, because the car comes to rest)

u = initial velocity (35 m/s)

a = acceleration (what we're trying to find)

s = distance over which the acceleration occurs (140 m)

Plugging the given values into the equation, we get:

\(0 = (35)^2 + 2 \cdot a \cdot 140\)

\(-1225 = 280a\)

\(a = \frac{-1225}{280}\)

\(a = -4.375 m/s^2\)

Therefore, the constant acceleration of the car is -4.375 m/s2, where the negative sign indicates that the car is decelerating.