A ship A is moving Westwards with a speed of 10 kmph and a ship B 100 km South of A, is moving Northwards with a speed of 10 kmph. The time after which the distance between them becomes the shortest is:
1. 0 h
2. 5 h
Two particles A and B, move with constant velocities v1 and v2 respectively. At the initial moment, their position vectors are r1 and r2 respectively. The condition for particles A and B for their collision will be
The position vector of a particle R as a function of time t is given by
Where R is in meters, t is in seconds and denote unit vectors along x and y-directions, respectively. Which one of the following statements is wrong for the motion of the particle?
1. Acceleration is along .
2. Magnitude of the acceleration vector is , where v is the velocity of the particle.
3. Magnitude of the velocity of the particle is 8 m/s.
4. Path of the particle is a circle of radius 4m.
A projectile is fired from the surface of the earth with a velocity of 5ms–1 and at an angle θ with the horizontal. Another projectile fired from another planet with a velocity of 3ms–1 at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the other planet is: (given g = 9.8 ms–2)
1. 3.5 m/s2
2. 5.9 m/s2
3. 16.3 m/s2
4. 110.8 m/s2
The velocity of a projectile at the initial point A is m/s. Its velocity (in m/s) at point B is:
The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is:
A particle moves in a circle of radius 5 cm with constant speed and time period sec. The acceleration of the particle is:
1. 25 m/s2
2. 36 m/s2
3. 5 m/s2
4. 15 m/s2
A body is moving with a velocity of 30 m/s towards the east. After 10 sec, its velocity becomes 40 m/s towards the north. The average acceleration of the body is:
A missile is fired for a maximum range with an initial velocity of 20 m/s. If g= 10 m/s2, then the range of the missile will be
1. 50 m
2. 60 m
3. 20 m
4. 40 m
A projectile is fired at an angle of 45º with the horizontal. Elevation angle of the projectile at its highest point, as seen from the point of projection, is :