a block of mass 1kg moving with a speed of 4m/s collides with another block of mass 2kg initially at rest. after the collision the lighter mass comes to a rest. what is the loss in the kinetic energy of the system?

True or false: the revolution of the earth creates day and night as it rotates around the sun

Who was the first scientist to measure speed as distance over time?

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)