consider 4 electron in 2 pairs of 2electron each. the first pair is in singlet state and the second pair is in triplet state with zero z component of the angular momentum. if we add the angular momenta of two pair how many z component values of the total angular momentum are possible

One hazard of space travel is debris left by previous missions. there are several thousand masses large enough to detect by radar orbiting the earth, but there are far greater numbers of very small masses such as flakes of paint. calculate the force exerted by a 0.110 mg chip of paint that strikes a space shuttle window at a relative speed of 5.00 ✕ 103 m/s and sticks, given the collision lasts 6.00 ✕ 10-8 s. such a collision chipped the window of the ill-fated challenger in june 1983, causing $50,000 of damage.