Q1. Two blocks of the same mass m, joined by a spring of negligible mass and with spring constant k, are being lowered at the end of a string with a downward acceleration of g/4. Beside how much is spring stretched as the blocks are lowered? The spring exerts an upward force of F on the top block.

2. A halfback on an apparent breakaway for a touchdown is tackled from behind. If the halfback has a mass of 98 kg and was moving at 4.1 m/s while he was tackled by an 85 kg cornerback running at 5.5 m/s in the similar direction, what was their mutual speed at once after the touchdown-saving tackle?

3. A proton moves at 5.60 × 106 m/s horizontally
loyack (cml2922) - HW-28 - oliver - (65000) 2
loyack (cml2922) - HW-28 - oliver - (65000) 3

at a right angle to a magnetic field. The acceleration of gravity is 9.81 m/s2. What is strength of the magnetic field necessary to exactly balance the weight of the proton and keep it moving horizontally?

Reply in units of T