Question

Starting from rest a car acquires a speed of 90 km/hr in 10 s, calculate the acceleration in this case.

• A. 2.5 cm/$s^2$
• B. 2.5 m/$s^2$
• C. 2.5 mm/$s^2$
• D. 25 m/$s^2$

Answer 1

The correct option is B 2.5 m/$s^2$

Given: u = 0 (since car starts from rest), v = 90 km/hr = $90\times \frac{5}{18}=25m/s$
So, using v = u + at, u = 0
We get, v = at
$\frac{v}{t}=\frac{25}{10}=2.5m/s^2$