robbers in a car travelling at 20m/s pass a policemen on a motorcycle at rest the policeman immediately starts chasing the robbers the policeman accelerate at 3 m/s2 for 12s and thereafter travels at a constant velocity calculate the distance covered by policeman before he overtakes the car
Answers
Answered by
18
Hello
Your answer,
◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾
Q. Robbers in a car travelling at 20m/s pass a policemen on a motorcycle at rest the policeman immediately starts chasing the robbers the policeman accelerate at 3 m/s2 for 12s and thereafter travels at a constant velocity calculate the distance covered by policeman before he overtakes the car
::::::::::::::::::::::::::::::::::::::::::::::
Solution :
The distance covered by the policeman in 12 sec
s = ut + 1/2 at2
= 0 x12 + 0.5 x3 x 12x12 = 216m
v = u + at = 0 + 12x3 = 36m/s
The distance covered by the robber in 12 sec
s = 20 x 12 = 240m
Suppose he over takes in 12 + t sec, in which he travels = 216 + 36 * t
r robbers will travel in the same time 20 * ( 12+t) m
216 + 36 t = 240 + 20 t
t = 24 / 16 = 1.5 s
Distance travelled by policeman in 12 + 1.5 = 13.5 s
= 216 + 36 x 1.5 = 270 m
◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾
Hope this will be helpful.
Your answer,
◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾
Q. Robbers in a car travelling at 20m/s pass a policemen on a motorcycle at rest the policeman immediately starts chasing the robbers the policeman accelerate at 3 m/s2 for 12s and thereafter travels at a constant velocity calculate the distance covered by policeman before he overtakes the car
::::::::::::::::::::::::::::::::::::::::::::::
Solution :
The distance covered by the policeman in 12 sec
s = ut + 1/2 at2
= 0 x12 + 0.5 x3 x 12x12 = 216m
v = u + at = 0 + 12x3 = 36m/s
The distance covered by the robber in 12 sec
s = 20 x 12 = 240m
Suppose he over takes in 12 + t sec, in which he travels = 216 + 36 * t
r robbers will travel in the same time 20 * ( 12+t) m
216 + 36 t = 240 + 20 t
t = 24 / 16 = 1.5 s
Distance travelled by policeman in 12 + 1.5 = 13.5 s
= 216 + 36 x 1.5 = 270 m
◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾◾
Hope this will be helpful.
Similar questions