Question

A racing car has a uniform acceleration 4m/s. What distance will it cover in 10 seconds after the start?

Answer 1

Uniform acceleration a = 4 m/s²

Initial velocity u= 0 m/s

Time t = 10 sec.

Velocity v after 10 sec= u + a t = 0 m/s + 4 m/s² × 10 s =40 m/s.

We shall calculate the distance covered by all possible methods

Using Average Velocity:

Initial velocity u= 0 m/s

Final velocity v= 40 m/s

Average velocity= ½( u +v) = ½ ( 0+40)= 20 m/s

Time= 10 s

Distance covered in 10 s= av. vel. × time= 20m/s × 10s = 200 m

Using the relation s = u t+ ½ a t²

u = 0 m/s, a = 4 m/s², t= 10 sec.

s = 0×10 + ½ 4× 10² = 200 m

Answer 2

Answer:

200m

Explanation:

acceleration=4m/s

u=0m

time=10s

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

at=v-u

4×10=v-0

v=40m

s=ut+1/2at2

s=0×10+1/2×4×10×10

s=200m