Answer:
F=1.4384×10⁻¹⁹N
Explanation:
Given Data
Charge q= -8.00×10⁻¹⁷C
Distance r=2.00 cm=0.02 m
To find
Electrostatic force
Solution
The electrostatic force between between them can be calculated from Coulombs law as

Substitute the given values we get

Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Assuming there is no force of friction...
F = ma
F = (1300kg)(1.5m/s^2)
F = 1950N
Just multiply mass by acceleration.
1300 x 1.5 = 1950N.
It is number 3 because I know it is