Question

a stationary car is accelerated at the rate of 5m/s^2. the distance covered by the cr till it reaches a speed of 40m/s is....
a. 100 m
b. 120 m
c. 160 m
d. 200 m​

Answer 1

V² - U² = 2aS

40² - 0² = 2*5*S

1600 = 10*S

So, S = 1600/10 = 160.

Therefore, till it reaches the speed of 40m/s it covers 160 m.

Answer 2

Given :

$\mathbf{Initial\ speed \ (u)= 0 \ \dfrac{m}{s}}$

$\mathbf{Finalal\ speed \ (v)= 40 \ \dfrac{m}{s}}$

$\mathbf{Acceleration\ of\ car \ (a)= 5 \ \dfrac{m}{s^{2}}}$

To Find:

The distance covered by the car till it reaches a speed of $\mathbf{40 \ \frac{m}{s}}$

Solution:

From equations of motion, we know the relation between final speed , initial speed , acceleration and distance is given below:

v² = u² + 2×a×s        ...1)

On putting respective value in above equation:

40² = 0² + 2×5×s  

1600 = 10×s

So

$\mathbf{s= \dfrac{1600}{10}}$

s = 160 m

So the distance covered by the car is 160 m.