Two pith balls of mass 10mg each are suspended by two threads from the same support are charged identically. They move apart by 0.08m and threads make an angle `60^@` with each other. Find the charge on each pith ball

Two forces 7 kgwt and 4 kgwt act at a point making an angle of 60^(@) with each other. Find the magnitude and direction of the resultant.

Two spherical balls of mass 10 kg each are placed with their centers 10 cm apart. Find the gravitational force of attraction between them. (AS_(1))

An unploarised beam of intensity I_(0) is incident on a pair of nicols making an angle of 60^(@) with each other. The intensity of light emerging from the pair is

Two forces P=5N and Q=10N are acting at a point making an angle of 30^(@) with each other. What is the value of the dot product of P and Q ?

(a) A circular coil of 30 turns and radius 8.0 cm carrying a current of 6.0 A is suspended vertically in a uniform horizontal magnetic field of magnitude 1.0 T. The field lines make an angle of 60^@ with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning. (b) Would your answer change, if the circular coil in (a) were replaced by a planar coil of some irregular shape that encloses the same area? (All other particulars are also unaltered.)

Two billiard balls each of mass 0.05 kg moving in opposite directions with speed 6 m s^(-1) collide and rebound with the same speed. What is the impulse imparted to each ball due to the other ?

Two small spheres of masses M_(1) and M_(2) are suspended by weightless insulating threads of lengths L_(1) and L_(2) The spheres carry charges Q_(1) and Q_(2) respectively. The spheres are suspended such that they are in level with one another and the threads are inclined to the vertical at angles of theta_(1) and theta_(2) as shown. Which one of the following conditions is essential, if theta_(1)=theta_(2) ?

Two particles of mass m each are tied at the ends of a light string of length 2a. The whole system is kept on a frictionless horizontal surface with the string held tight so that each mass is at a distance 'a' from the center P (as shown in figure). Now, the mid-point of the string is pulled vertically upwards with a small but constant force F. As a result, the particles move towards each other on the surface. The magnitude of acceleration, when the separation between them becomes 2x, is :