Atoms of i-131 spontaneously decay when the (1) stable nuclei emit alpha particles (2) stable nuclei emit beta particles (3) unstable nuclei emit alpha particles (4) unstable nuclei emit beta particles

Explain vector addition, triangle method and parallelogram method

What are similarities and differences of reflection, refraction, diffraction and absorption?

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.