An ant is moving on the surface of a ball. Does it’s velocity change or not? Explain.

On a frictionless horizontal surface , assumed to be the x-y plane , a small trolley A is moving along a straight line parallel to the y-axis ( see figure) with a constant velocity of (sqrt(3)-1) m//s . At a particular instant , when the line OA makes an angle of 45(@) with the x - axis , a ball is thrown along the surface from the origin O . Its velocity makes an angle phi with the x -axis and it hits the trolley . (a) The motion of the ball is observed from the frame of the trolley . Calculate the angle theta made by the velocity vector of the ball with the x-axis in this frame . (b) Find the speed of the ball with respect to the surface , if phi = (4 theta )//(4) .

Two balls are moving on the same smooth horizontal plane. Their velocity components along one adge of the square plane are 10sqrt(3)m//s & 20 m//s respectively. Their velocity components along a perpenficular edge are 30 m//s & 20 m//s . Find the angle between their directions of motion.

A particle is moing with a velocity of 10m//s towards east. After 10s its velocity changes to 10m//s towards north. Its average acceleration is:-

How does the resistance of a wire vary with its area of cross-section? Explain.

A point moves along an arc of a circle of radius R. Its velocity depends on the distance covered s as v=asqrts , where a is a constant. Find the angle alpha between the vector of the total acceleration and the vector of velocity as a function of s.

If a liquid does wet the surface ,its angle of contact is acute or obtuse ?

The escape velocity on the surface of earth is 11.2 km/s. What will be its value on a planet having double the radius and eight times the mass of earth?

What is the deceleration of a vehicle moving in a straight line that changes its velocity from 100 km/h to a dead stop in 10s?