Speed And Velocity

Consider an inertial frame S' moving at a speed away from another inertial frame S along the common x-axis, where c is the speed of light. As observed from S', a particle is moving with speed in the y' direction as shown in the figure. The speed of the particle as seen from S will be

If the stream function equation y=3x²-y², what is the magnitude of velocity at point (2.2)?

What will be drift velocity of the free electron in a copper wire whose cross sectional area is A = 1.00 mm² when the wire carries a current of 1.0 A. Assume that each copper atom contributes 1 electron to the electron gas. (Given density of copper = 8.94x10³ kg/m³, atomic mass of copper = 63.5 u, 1 u = 1.66x10^-27 kg)

Electrons are accelerated by 344 volts and reflected from the crystal. The first reflection maximum occurs when glancing angle is 30°. What will be the value of interplanar spacing of the crystal? [Given h=6.62×10^-34 Js, m_e = 9.1x10^-31 kg]

A bullet of mass 10 g moving horizontally with a speed of 500 m/s passes through a block of wood of mass 1 kg, initially at rest on a frictionless surface. The bullet comes out of the block with a speed of 200 m/s. What is the final speed of the block?