NIFT UG 2015 Question Paper with solutions

Question : 49 of 150

Marks: +1, -0

A car starts with a speed of 20 km/h and increases its speed by 10 km/h after every hour. Another car has a constant speed of 50 km/h. In how much time, both the cars cover equal distance?

4 hours
5 hours
6 hours
7 hours

Validate

Solution:

For car-I, initial speed u = 20 km/h
Acceleration

a=10\text "km/h"^2

Distance travelled by car-I in time t

=20t+1/2(10)t^2

=20t+5t^2

Distance travelled by car-II in time t = 50t From question,

20t+5t^2=50t

30t=5t^2

5t(t-6)=0

∴ t = 6 hours

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