It is found that when a man increases his speed by "2m/s" ,his kinetic energy is doubled. His original speed was ?

If a man increase his speed by 2m/s, his K.E. is doubled, the original speed of the man is

On increasing the speed of a bosy to 2ms^(-1) , its kinetic energy is quadrupled. Then is original speed must be

If the speed of a vehicle is increased by 1 ms^(-1) , its kinetic energy is doubled , then original speed of the vehicle is

A man who is running has half the kinetic energy of a boy of half his mass. The man speeds up by 1 ms^(-1) and then has the same kinetic energy as the boy. The original speed of the boy was:

Amit covers a certain distance with his own speed but when he reduces his speed by 10 km/h his time duration for the journey increases by 40 hours , while if he increases his speed by 5 km/h from his originAl speed he takes 10 hours less than the original time taken. find the distance covered by him.