The force of gravity on objects is proportional to the mass of each object.
(That's a big part of the reason why, when you eat more and your mass
increases, you weigh more.)
The forces of gravity between the Earth and the 6kg ball are 50% greater
than the forces of gravity between the Earth and the 4kg ball.
(The gravitational forces between the 4kg ball and the 6kg ball, or between
both bowling balls and you, are so small that they may be ignored.)
Beats.
When two sound waves of different frequency approach your ear, the alternating constructive and destructive interference causes the sound to be alternatively soft and loud - a phenomenon which is called "beating" or producing beats. The beat frequency is equal to the absolute value of the difference in frequency of the two waves.
Total mechanical energy = kinetic energy + potential energy
E = KE + PE
E = ½mv² + mgh
E = ½(0.1 kg)(2 m/s)² + (0.1 kg)(9.8 m/s²)(1.5 m)
E = 0.2 J + 1.47 J
E = 1.67 J
1. I think it's the trails left by an electron as it moves around the nucleus.
2. The atomic number is the number of protons so it is 8.
3. It's mass is lowered but it is still the same element.