A car is moving with a velocity of 10m/s can be stopped by the applica

1.	A car is moving with a velocity of 10m/s can be stopped by the application of a constant force F in a distance of 20m.If the velocity of the car is 30m/s,it can be stopped by this force in?
Answer» Answer: The car can be STOPPED by this force in 180 m. Explanation: GIVEN that, velocity of car = 10 m/s distance s = 20 m Let the mass of the car be m. Case (I). Using equation of motion $v^2 =u^2+2as$ $0=10^2+2a\times20$ $a =-\dfrac{100}{40}\ m/s^2$ Negative sign shows the retardation because the speed is decreasing. For case (II), Velocity v = 30 m/s The force is same. So, The acceleration will be same. Using equation of motion again $v^2=u^2+2as$ $0=30^2+2as$ $s = \dfrac{-30^2}{2\times\dfrac{-100}{40}}$ $s = 180\ m$ Hence, The car can be stopped by this force in 180 m.