Answer:
1. 75N
2. 67,983 J (=67.98 kJ)
Explanation:
1. Work = Force x Distance
we are given that Work = 1,500J and Distance = 20m
hence,
Work = Force x Distance
1,500 = Force x 20
Force = 1,500 ÷ 20 = 75N
2. Potential Energy, PE = mass x gravity x change in height
we are given that mass = 165 kg and change in height = 42m
assuming that gravity, g = 9.81 m/s²
Potential Energy, PE = mass x gravity x change in height
Potential Energy, PE = 165 x 9.81 x 42 = 67,983 J (=67.98 kJ)
<u>Answer:</u> The number of electrons in given amount of silver are 
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

We are given:
Given mass of silver = 7.1 g
Molar mass of silver = 107.87 g/mol
Putting values in above equation, we get:

Number of electrons in 1 atom of silver = 47
According to mole concept:
1 mole of an element contains
number of particles
So, 0.066 moles of silver will contain = -
number of electrons
Hence, the number of electrons in given amount of silver are 
All the bats living in a cave form a __colony__of bats in the cave ecosystem.