Q#2: The velocity of a Bus is reduced uniformly from 15 m/s to 7 m/s while
traveling a distance of 90 m
1. Compute the acceleration,
How much further will the Bus travel before coming to rest, provided the acceleration
remain constant?
Answers
Answer:-
• Acceleration of the bus = -0.98m/s²
• Distance travelled by the bus further
before coming to rest = 24.8m
Explanation:-
Firstly, let's calculate the acceleration of the bus by using the 3rd equation of motion :-
=> v² - u² = 2as
Where:-
• v is final velocity of the bus .
• u is initial velocity of the bus.
• a is acceleration of the bus.
• s is distance travelled.
=> (7)² - (15)² = 2×a×90
=> 49 - 225 = 180a
=> -176 = 180a
=> a = -176/180
=> a = -0.98m/s²
Now in the 2nd case, we have to calculate the distance covered by the bus further before coming to rest.
Hence, in this case :-
• Final velocity of the bus will be zero as
it finally comes to rest.
=> v² - u² = 2as
=> 0 - (15)² = 2(-0.98)s
=> -225 = -1.96s
=> s = -225/-1.96
=> s = 114.8m
So, the bus travels a total distance of 114.8m before coming to rest. But we have to calculate the distance travelled by the car after it had initially covered 90m.
Thus, distance travelled furtherwards :-
= 114.8 - 90
= 24.8m