Answer:
Question #1- Scientists agree to a standard way of reporting measured quantities in which the number of reported digits reflects the precision in the measurement- more digits, more precision; less digits, less precision. You just studied 14 terms!
Question #2- Units are important because without proper measurement and units to express them, we can never express physical laws precisely just from qualitative reasoning. Units are incredibly important to physics. Two of the most important reasons are the following: (1) they help us. to avoid making mistakes in computation, and (2) they serve as a check on computations once they are completed. In the first case, you can avoid adding 3m and 25cm and coming up with the wrong answer.
Explanation: Hope this helps please mark brainliest!
Answer:
The periodic table illustrate some of the elements from Hydrogen to Calcium
The gravitational forces between the Earth and Moon are greatest when the two bodies are closest together. That happens every 27.32 days, when the Moon is at the perigee of its orbit.
Even if this happened at the same time in every orbit, the date would change, because there are not 27.32 days in a month.
But it doesn't happen at the same time in every orbit ... the Moon's perigee precesses around its orbit, on account of the gravitational forces toward the Earth, the Sun, Venus, Mars, and the other planets.
Answer: a) 8.2 * 10^-8 N or 82 nN and b) is repulsive
Explanation: To solve this problem we have to use the Coulomb force for two point charged, it is given by:

Replacing the dat we obtain F=82 nN.
The force is repulsive because the points charged have the same sign.
Answer:
1. 37.8J
2. 18 Billion Joules, 18 Gigajoules
3. 9.81 Billion Joules, 9.81 Gigajoules
Explanation:
Use the formulas provided,
KE=(1/2)mv^2 and PE=mgh, noting that g=9.81