Answer:

Explanation:
The formula for the velocity of the ball is

1. Velocity at time of impact

2. Velocity on rebound
The ball has enough upward velocity to reach a height of 0.86 m.

3. Acceleration

Answer:kapil
Explanation:
Atoms lose electrons, if an electron gets more energy than then binding energy of the electron. This may be because of a collision with a charged particle or because of absorbtion of a photon. In a metal, there are just other positive charges nearby. The electron is not lost, but shared.
In science it is best to continue research, and rinse and repeat. This allows for a stronger hypothesis if you're results are the same every time, or change your hypothesis if you stumble upon new results. <span />
To find this, we will use this formula:
Molar mass of element
------------------------------------ x 100
Molar mass of compound
So, first lets calculate the mass of the compound as a whole. We use the atomic masses on the periodic table to determine this.
Ca: 40.078 g/mol
N2 (there is two nitrogens): 28.014 g/mol
O6 (there are six nitrogens: 3 times 2): 95.994 g/mol
When we add all of those numbers up together, we get 164.086. That is the molar mass for the whole compound. However, we are trying to figure out what percent of the compound oxygen makes up. From the molar mass, we know that 95.994 of the 164.086 is oxygen. Lets plug those numbers into our equation!
95.994
-----------
164.086
When we divide those two numbers, we get .585. When we multiply that by 100, we get 58.5.
So, the percent compostition of oxygen in Ca(NO3)2, or, calcium nitrate, is 58.5%.