A small spherical ball of mass m slides without friction from the top of a hemisphere of radius R. At what height will the ball lose contact with surface of the sphere ?
f A = B + C have scalar magnitudes of 5, 4, 3 units respectively, then the angle between A and C is
cos-1 (3/5)
cos-1 (4/5)
π/2
sin-1 (3/4)
A particle is projected from the ground with a kinetic energy E at an angle of 60° with the horizontal. Its kinetic energy at the highest point of its motion will be
E/2
E/4
E/8
A bullet on penetrating 30 cm into its target loses its velocity by 50%. What additional distance will it penetrate into the target before it comes to rest ?
30 cm
20 cm
10 cm
5 cm
The velocity of a projectile at the initial point A is (2i + 3j) m/s. Its velocity (in m/s) at point B is
− 2i − 3j
− 2i + 3j
2i − 3j
2i + 3j
C.
2i − 3j
From the figure the X-component remain unchanged, while the Y-component is reverse. Then, the velocity at point B is (2i − 3j) ms-1.
A small object of uniform density rolls up a curved surface with an initial velocity v'. It reaches up to a maximum height of with respect to the initial position. The object is
ring
solid sphere
hollow sphere
disc
Consider three vectors , and . A vector X of the form (α and β are numbers) is perpendicular to C. The ratio of α and β is
1 : 1
2 : 1
− 1 : 1
3 : 1
A cricket ball thrown across a field is at heights h1 and h2 from the point of projection at times t1 and t2 respectively after the throw. The ball is caught by a fielder at the same height as that of projection. The time of flight of the hall in this journey is
A wooden block is floating on water kept in a beaker. 40% of the block is above the water surface. Now the beaker is kept inside a lift that starts going upward with acceleration equal to g/2. The block will then
sink
float with 10% above the water surface
float with 40% above the water surface
float with 70% above the water surface