a motor bike moving with a speed of 54km/h on applying brake stopped in 8 sec calculate the acceleration?
Answers
Answer:we know that ,
From first law,
V=u+at
From the above,v=0
u+at=0
54+a(8)=0
8a=-54
a=-54/8=6.75km/s²
Explanation:
Hope it helps you...
A motor bike moving with a speed of 54km/h on applying brake stopped in 8 sec.
We have to find the acceleration of the motor bike.
From above data we have; initial velocity is 54 km/hr, final velocity is 0 km/hr and time is 8 sec.
Firstly convert km/hr into m/s. To do this, multiply the value of 5/18.
→ Initial velocity = 54*5/18 = 15 m/s, final velocity = 0 m/s.
First equation of motion:
v = u + at
Second equation of motion:
s = ut + 1/2 at²
Third equation of motion:
v² - u² = 2as
Using the first equation of motion i.e. v = u + at
Substitute the values,
→ 0 = 15 + a(8)
→ -15 = 8a
→ -1.875 = a
(Negative sign shows retardation)
Therefore, the acceleration of the motor bike is -1.875 m/s².