Rain is falling vertically with a speed of 30 ms-1. A man rides a bicycle with a speed of 10 ms-1 in north to south direction. The angle with the vertical at which the man should hold his umbrella to protect himself from the rain is:
None of these
A vector of magnitude a is rotated through angle θ. The magnitude of change in the vector is
2a sin θ
2a cos θ
The value of p so that vectors and are perpendicular is
6
3
2
Two particles having different speeds when approach each other, the distance between them decreases at the rate of 6ms-1 .If the particles move in the same direction, the distance between them increases at the rate of 4 ms-1. The speeds of the particles are
2, 10
6, 2
5, 1
4, 1
is written by some student. Then, it
is not possible
has the same direction as that of
has direction opposite to that of
has no definite direction
A rod of length PQ = l leans by its upper end against a smooth vertical wall while its end leans against the base. The end Q of the rod moves uniformly downward with speed v1. The end P will move on the floor with velocity v2 such that :
v2 is uniform and v2 = v1
v2 is uniform but v2 ≠ v1
v2 continuously increases
v2 continuously decreases
The force acting on a body of 10 kg is N. If the body is initially at rest, then velocity at the end of 20 sec will be (in m/s).
2√6
6√2
3√2
2√3
A person walks up a stationary escalator in time t1. If the person remains stationary on the escalator, then it can take him up in time t2. The time that would it take him to walk up the moving escalator is
t1 - t2
t2 - t1
Two equal vectors have a resultant equal to either of them. The angle between them is
60o
90o
100o
120o
The angle between the two vectors will be
0o
45o
180o
