Motion of a particle is given by equation s = (3t³ + 7t² + 14t + 8) m. The value of acceleration of the particle at t = 1 sec is

The width of river is 1 km. The velocity of boat is 5 km/hr. The boat covered the width of river in shortest time 15 min. Then the velocity of river stream is

Two projectiles of same mass and with same velocity are thrown at an angle 60^o and 30^o with the horizontal, then which will remain same

A man is slipping on a frictionless inclined plane and a bag falls down from the same height. Then the velocity of both is related as