Question

If an object accelerates from rest to velocity 30 m/s in 10 s, then the distance covered by the object during the next 10 s is

• A. 450 m
• B. 300 m
• C. 150 m
• D. 600 m

Answer 1

The correct option is A 450 m

For the first 10 s:
Initial velocity, u = 0 (As the object starts from rest)
Final velocity, v = 30 m/s
Time, t = 10 s
Using first equation of motion, v = u + at
Acceleration, $a=\frac{v-u}{t}=\frac{30-0}{10}$
$\Rightarrow a=3m/s^2$
For the next 10 s:
Initial velocity, u = 30 m/s
Time, t = 10 s
Acceleration, $a=3m/s^2$
Using second equation of motion, $s=ut+\frac{1}{2}a{t}^2$
$\Rightarrow s=30\times 10+\frac{1}{2}\times 3\times (10{)}^2$
$\Rightarrow s=300+150$
$\Rightarrow s=450m$
Hence, the correct answer is option (a).