Answer:
C
Sign-Negative
Explanation:
We are given that
Electric field = (Radially downward)
Acceleration=(Upward)
Mass of charge=3 g=kg
1kg=1000g
We have to find the magnitude and sign of charge would have to be placed on a penny .
By newton's second law
Substitute the values then we get
Substitute the values then we get
C
Sign of charge =Negative
Because electric force acting in opposite direction of electric field therefore,charge on penny will be negative.
Answer:
The minimum frequency required to ionize the photon is 111.31 × Hertz
Given:
Energy = 378
To find:
Minimum frequency of light required to ionize magnesium = ?
Formula used:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
Solution:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
738 × = 6.63 ×
× v
v = 111.31 × Hertz
The minimum frequency required to ionize the photon is 111.31 × Hertz