INITIAL VELOCITY =20m/s=u
FINAL VELOCITY =5m/s=v
TIME TAKEN = 2 sec = t
Acceleration = ? = a
We have
a = [ V - U ] / f
= [ 5 - 20 ] /2 =7 .5 m/s2
ANSWER IS 7.5 m/s2
Answer
Find out the calculate the acceleration if it took 3 seconds to slow your car down .
To prove
The formula of the accleration is given by
[tex]a = \frac{v_{f} - v_{i}}{t}[/tex]
[tex]where\ v_{f}\ is\ the\ final\ velocity.[/tex]
[tex]where\ v_{i}\ is\ the\ intial\ velocity.[/tex]
t is the time.
As given
you are traveling in a car that is moving at a velocity of 20 m/s.
suddenly a car 10 meters in front of you slams on its brakes.
at the moment you also slam on your brakes and slow to 5 m/s and it take 3 seconds.
[tex]v_{f} = 5m/s[/tex]
[tex]v_{i} = 20m/s[/tex]
t = 3s
put all the value in the formula
[tex]a = \frac{5 - 20}{3}[/tex]
[tex]a = \frac{-15}{3}[/tex]
a = -5 m/s²
Therefore the acceleration is -5 m/s² .
