Physics · Forces and Motion
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A cyclist is travelling at 15 ms-1, she applies brakes so that she doesn't collide with the wall in front of her at a distance of 18 m. Calculate the magnitude of deceleration.
- A
6.3 ms-2
- B
5.3 ms-1
- C
13 ms-1
- D
12.5 ms-1
Initial velocity, u=15m/s
Final velocity, v=0m/s
Distance, s=18m
Acceleration, a=?
Using relation, v2 −u2 =2as
02 −(15)2 =2a×18
−225=36a
a= 36 −225 =−6.25m/s2
So, deceleration is 6.25m/s2 which is equal 6.3m/s2
Initial velocity, J = 15m / s
Final velocity, v = 0m / s
Distance, s = 18m, Acceleration, a=?
Using relation, v2 - u2 = 2as
02 - (15)2= 2a×18
- 225 = 36a
a = -225/ 36 = - 6.25 m /s2
So, deceleration is 6.25m/s² which is equal to 6.3m/s².
This is incorrect as per explanation.Initial velocity, J = 15m / s
Final velocity, v = 0m / s
Distance, s = 18m, Acceleration, a=?
Using relation, v2 - u2 = 2as
02 - (15)2= 2a×18
- 225 = 36a
a = -225/ 36 = - 6.25 m /s2
So, deceleration is 6.25m/s² which is equal to 6.3m/s².
This is incorrect as per explanation.Initial velocity, J = 15m / s
Final velocity, v = 0m / s
Distance, s = 18m, Acceleration, a=?
Using relation, v2 - u2 = 2as
02 - (15)2= 2a×18
- 225 = 36a
a = -225/ 36 = - 6.25 m /s2
So, deceleration is 6.25m/s² which is equal to 6.3m/s².
This is incorrect as per explanation.Initial velocity, J = 15m / s
Final velocity, v = 0m / s
Distance, s = 18m, Acceleration, a=?
Using relation, v2 - u2 = 2as
02 - (15)2= 2a×18
- 225 = 36a
a = -225/ 36 = - 6.25 m /s2
So, deceleration is 6.25m/s² which is equal to 6.3m/s².
Tagged under Physics · Forces and Motion · 2018