Question

A car accelerates uniformly from 18 km per hour to 36 kilometre per hour within a distance of 15m . the uniform acceleration of the car is is

Answer 1

→GIVEN←

A car accelerates uniformly from 18 km per hour to 36 kilometre per hour within a distance of 15 m.

Initial velocity, u = 18 km/h

Final velocity, v = 36 km/h

Distance, s = 15 m

→TO FIND←

The acceleration (a) of the car.

→SOLUTION←

Converting the velocities from km/h to m/s :-

◙ 18 km/h = 18 × (5/18) = 5 m/s

◙ 36 km/h = 36 × (5/18) = 5 × 2 = 10 m/s

Now, we know :-

$\boxed{\rm{\ddag\ v^2=u^2+2as}}$

Substituting the values :-

$\rm{\rightarrowtail (10)^2=(5)^2+2\times a \times 15}\\\\\rm{\rightarrowtail 100=25+30a} \\\\\rm{\rightarrowtail 75=30a} \\\\\rm{\rightarrowtail a=\dfrac{75}{30} } \\\\\rm{\rightarrowtail a=\dfrac{5}{2} } \\\\\boxed{\rm{\rightarrowtail a=2.5\ m/s^2} }$

Therefore, the car has an acceleration of 2.5 m/s².

Answer 2

Answer:

2.5 ms

Explanation:

use 3rd equation of motion

v

$v {2} = u2 + as$

and finished