Question

The velocity of an object increases at a constant rate from $20m{s}^{-1}$ to $50m{s}^{-1}$in 10 s. Find the acceleration.

• A. $-3m{s}^{-2}$
• B. $-30m{s}^{-2}$
• C. $30m{s}^{-2}$
• D. $3m{s}^{-2}$

Answer 1

Answer: (D)

$3m{s}^{-2}$

Acceleration $a=\frac{v-u}{t}=\frac{50m{s}^{-1}-20m{s}^{-1}}{10s}$
or $a=\frac{30m{s}^{-1}}{10s}$
$=3m{s}^{-2}$