Answer:
v = 45.37 m/s
Explanation:
Given,
angle of inclination = 8.0°
Vertical height, H = 105 m
Initial K.E. = 0 J
Initial P.E. = m g H
Final PE = 0 J
Final KE = 
Using Conservation of energy




v = 45.37 m/s
Hence, speed of the skier at the bottom is equal to v = 45.37 m/s
Answer:
Average speed is 60 km/hour
Explanation:
When we need to calculate average speed, we use this equation:

Where:
position at the beginning
at the end


Then: 

Finally V = 60 km/hour
Answer:
O²⁻
Explanation:
Number of protons = 8
Number of neutrons = 9
Number of electrons = 10
What type of atom or ion is it = ?
Solution:
Protons are the positively charged particle in an atom
Neutrons do not carry any charges
Electrons are negatively charged particles
For this atom, the number of protons helps to identify what specie it is; so this is an oxygen atom.
Now,
Charge = Number of protons - Number of electrons
Charge = 8 - 10 = -2
The charge on the atom is -2 and so it is an oxygen ion with -2 charge
The ion is O²⁻