The displacement $$x$$ of a particle in a straight line motion is given by $$x=1-t-t^2$$. The correct representation of the motion is

Two guns P and Q can fire bullets at speeds 2 km/s and 4 km/s, respectively. From a point on a horizontal ground, they are fired in all possible directions. The ratio of maximum or areas covered by the bullets fired by the two guns, on the ground is

A car is moving with a speed of 54 km/h. If after 3 s, the driver applies brakes and it stops, then how much distance is covered by the car before coming to rest?

Which graph shows the correct $$v$$ - $$x$$ graph of a freely falling body?