A particle is moving westward with a velocity Its velocity changed to northward. The change in velocity vector is:
(1) towards north east
(2) towards north west
(3) zero
(4) towards north west
Consider east as positive x-axis, north as positive y-axis and vertically upward direction as z-axis. A helicopter first rises up to an altitude of 100 m than flies straight in north 500 m and then suddenly takes a turn towards east and travels 1000 m east. What is position vector of helicopter. (Take starting point as origin)
(1)
(2)
(3)
(4)
A force Newton produces acceleration in a body. The mass of the body is (in kg)
(1)
(2)
(3)
(4)
Given the vectors
Find the angle between
(A)
(B)
(C)
(D) none of these
The vector having a magnitude of 10 and perpendicular to the vector is-
1.
2.
3.
4.
A force acting on a particle causes a displacement . If the work done is 6J then the value of 'c' is-
1. 12
2. 0
3. 6
4. 1
A particle moving along a straight line according to the law , where x is its position measured from a fixed point on the line and t is the time elapsed till it reaches position x after starting from the fixed point. Here A, B and C are positive constants.
(1) Its velocity at t=0 is A
(2) Its acceleration at t=0 is B
(3) Its velocity at t=0 is B
(4) Its acceleration at t=0 is C
If the velocity of a particle moving on x-axis is given by . At which time is the acceleration of particle zero?
1. sec
2. sec
3. sec
4. zero
Momentum of a body moving in a straight line is . Find the force acting on a body at t=2 sec
(1) 6 N
(2) 8 N
(3) 4 N
(4) 2 N
A particle moves along straight line such that at time t its position from a fixed point O on the line is . The velocity of the particle when t=2 is:
(A)
(B)
(C)
(D)