Question

The brakes applied to a car produce and negative acceleration of 10 metre per second if the car takes 5 seconds to stop after applying the brakes calculate the distance covered by the car before coming to rest

Answer 1

HI there !

Initial velocity = u 

Final velocity = v = 0

acceleration = a = -10 m/s²  [ retardation ]

Time = t = 5 sec

Equation of motion :-

v = u + at

0 = u + -10 × 5

0 = u  + [-50]

u = 50 m/s

s = distance covered by the car before coming to rest 

Equation of motion :-

s = ut + 1/2 at²
 
   = 50 × 5 + 1/2 × -10 × 5 × 5
  
   = 125 metres

Answer 2

ANSWER:-
Given:
a= - 10 m/s².
t = 5 sec.
v = 0 m/s
We know that v= u +at,so by appying the values we get,
=>0 = u + (-10)×5.
=>u = 50 m/s.
=>s = ut + (1/2)at²(applying 2nd law of motion) .
= 50×5 + (1/2)×(-10)×(5)²
= 250 -125 = 125 m.