Optics — Physics STD 11 Science — Question

In a projectile motion, velocity at maximum height is

Select the WRONG statement.

A bullet strikes a plank of thickness 5 cm with a velocity of 1000 m/s and emerges out with a velocity of 400 m/s, the average retardation of the bullet is

Which of the following type of radiations are radiated by an oscillating electric charge?

A shell fired from a canon can cover maximum horizontal distance of 10 km. Then velocity of projection is

Point masses of 2 kg, 3 kg, 5 kg and 7 kg are placed at the corners of a square ABCD respectively whose each side is 1 m long. The position of the centre of mass of the system is

In semiconductors at room temperature,

A marble of mass X collides with a block of mass Z, with a velocity Y. and sticks to it. The final velocity of the system is

A coolie holding a suitcase on his head of 20 kg and travels on a platform. then work done in joule by the coolie is