In an alpha decay, an atom emits an alpha particle. An alpha particle consists of 2 protons and 2 neutrons: this means that during this kind of decay, the original atom loses 2 protons and 2 neutrons from its nucleus.
This also means that the atomic number Z of the element (the atomic number is the number of protons in the nucleus) decreases by 2 units in the process, while the mass number A (the mass number is the sum of the number of protons and neutrons) decreases by 4 units.
C. The higher the altitude the less gravity affects you
Planets in our solar system do not revolve around the sun in perfect circles. Their orbits are more like ovals that scientists describe as elliptical. It is one of Kepler's laws. The sun is the focus of all the planets. The correct answer is D.
Answer:
Slope = 2 m / 10 m = 1/5
For every 5 m of effort the object will be raised 1 m
W = work done on object = M g h increase in PE of object
E S = W where E is effort and S the distance thru which the effort acts
E S = M g H
E = 100 kg * 9.8 m/s^2 * 2 m / 10 m = 196 kg m / s^2 = 196 N
Check: total work = 2 * 9.8 * 100 = 1960 J
Force Needed = 1960 J / 2 m = 980 Newtons
Mechanical advantage = 980 / 196 = 5 as one would expect since the object is raised 1 m for every 5 m of force input
