Question

A car traveling in a straight line has a velocity of +2.3 m/s. After an acceleration of 0.74 m/s2, the car's velocity is +8.4 m/s. In what time interval did the acceleration occur?

Answer 1

A car traveling in a straight line has a velocity of $+2.3 \, \text{m/s}$. After an acceleration of $0.74 \, \text{m/s}^2$, the car's velocity is $+8.4 \, \text{m/s}$. In what time interval did the acceleration occur?

Solution.

$$v_0 = 2.3 \frac{m}{s}, \quad a = 0.74 \frac{m}{s^2}, \quad v = 8.4 \frac{m}{s};$$ $$t - ?$$

Velocity is:

$$v = v_0 + a t.$$

The time interval is:

$$t = \frac{v - v_0}{a}.$$ $$t = \frac{8.4 - 2.3}{0.74} = 8.2(s).$$

Answer: $t = 8.2s$.