A point moves in a straight line so that its displacement x metre at time t sec is given by . Its acceleration in m/s2 at time t sec is
1.
2.
3.
4.
A ball is falling freely strikes to ground with velocity
60 m/s. Height fallen in last one second before
hitting the ground is
1. 55 m
2. 70 m
3. 60 m
4. 80 m
The x and y coordinates of the particle at any time are and y = 10 t respectively, where x and y are in meters and t in seconds. The acceleration of the particle at t = 2 s is
1. 0
2. 5
3. -4
4. -8
Two point masses 1 and 2 move with uniform velocities respectively. Their initial position vectors are respectively. Which of the following should be satisfied for the collision of the point masses ?
1.
2.
3.
4.
A bus moves over a straight level road with a constant acceleration a. A body in the bus drops a ball outside. The acceleration of the ball with respect to the bus and the earth are respectively
(1) a and g
(2) a + g and g - a
(3)
(4)
A ball is dropped on the floor from a height of 10 m. It rebounds to a height of 2.5 m. If the ball is in contact with the floor for 0.01 s, the average acceleration during contact is nearly (Take g = 10 m)
(1)
(2)
(3)
(4)
Two bullets are fired horizontally and simultaneously towards each other from the rooftops of two buildings (building being \(100~\text{m}\) apart and being of the same height of \(200~\text{m}\)) with the same velocity of \(25~\text{m/s}\). When and where will the two bullets collide? \(\left(g = 10~\text{m/s}^2 \right)\)?
1. | after \(2~\text{s}\) at a height of \(180~\text{m}\) |
2. | after \(2~\text{s}\) at a height of \(20~\text{m}\) |
3. | after \(4~\text{s}\) at a height of \(120~\text{m}\) |
4. | they will not collide. |
A point moves in a straight line under the retardation . If the initial velocity is u, the distance covered in 't' second is-
1. aut
2.
3.
4.
The relation between time and distance is , where and are constants. The retardation is
1.
2.
3.
4.
A particle moves along a parabolic path y = 9x2 in such a way that the x component of the velocity remains constant and has a value of . It can be deduced that the acceleration of the particle will be:
1.
2.
3.
4.