Question

A car decreases its speed from $80\frac{km}{h}$ to $60\frac{km}{h}$ in 5 second. The acceleration of the car is:

• A. -1.11 m/s²
• B. 1.12 m/s²
• C. -1.14 m/s²
• D. 1.11 m/s²

Answer 1

The correct option is A

-1.11 m/s²

Here,

$u=80\frac{km}{h}=22.22\frac{m}{s}$

$v=60\frac{km}{h}=16.67\frac{m}{s}$

t = 5s

Using, $a=\frac{v-u}{t}$

$a=\frac{16.67-22.22}{5}$ ${\frac{m}{s}}^2$

$a=-1.11\frac{m}{s^2}$