A car is travelling on a straight level road with a speed of 60 km/hr is followed by another car B which is moving with a speed of 70 km/hr.When the distance between them is 2.5 km,The B car is given an accelaration of 20km/hr.After what distance and time will the car B catch up with car A?
Answers
Answered by
3
Answer:
Explanation:
Speed of car A = 60 km/hr (Given)
Speed of car B = 70 km/hr (Given)
Distance d = 2.5 km (Given)
Acceleration of car B = 20km/hr
Let car A moves at time = t
The distance of car A is = 60t
The distance of car B is , using equation of motion -
s= ut+1/2at²
sB = 70t + 10t²
Time = s = sA-sB
2.5 = 70t + 10t² - 60t
2.5 = 10t + 10t²
10t + 10t²- 2.5 = 0
t = 12 min
Thus, the distance of car B -
sB = 70 × 0.21 + 10(0.21)²
sB = 15km
Therefore, , car B will catch up with car A after 12 minutes at the distance of 15 km.
Similar questions