Question

p. 16 left-side example problems • a car is at a stop light. calculate the acceleration as it reaches a velocity 30 m/s in 5s.

Explanation:

Step1: Recall acceleration formula

Acceleration \( a \) is defined as the change in velocity \( \Delta v \) over time \( \Delta t \), so \( a = \frac{\Delta v}{\Delta t} \). The initial velocity \( v_0 = 0 \, \text{m/s} \) (at stop light), final velocity \( v = 30 \, \text{m/s} \), time \( t = 5 \, \text{s} \). So \( \Delta v = v - v_0 = 30 - 0 = 30 \, \text{m/s} \).

Step2: Calculate acceleration

Substitute \( \Delta v = 30 \, \text{m/s} \) and \( \Delta t = 5 \, \text{s} \) into the formula: \( a = \frac{30}{5} = 6 \, \text{m/s}^2 \).

Answer:

The acceleration of the car is \( 6 \, \text{m/s}^2 \).