The transmutation of a radioactive uranium isotope, 234/92u , into a radon isotope, 222/86rn , involves a series of three nuclear reactions. at the end of the first reaction, a thorium isotope,230/90th , is formed and at the end of the second reaction, a radium isotope, 226/88ra , is formed. in both the reactions, an alpha particle is emitted. write the balanced equations for the three successive nuclear reactions.

According to newton’s first law of motion, which force is expected to cause a body to accelerate?

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d