Answer:
0.0006091222 m
Explanation:
q = Charge = 42 pC
V = Voltage = 620 V
= Permittivity of free space = 
Electric potential is given by (at r = R)

The radius of the drop is 0.0006091222 m
Answer:
(a) 30 m/sec
(b) -50 m/sec
Explanation:
We have given initial velocity of ball u = 50 m/sec
Acceleration due to gravity 
(a) Time t = 2 sec
Now according to first equation of v = u-gt
So v=50-10×2=30 m/sec
(b) Time t = 10 sec
Now according to first equation of motion
So final velocity v = u-gt = 50-10×10 =-50 m/sec
Answer:
D. 5m
Explanation:
fλ = c, where f is frequency, λ is wavelength and c is speed.
6λ=30
λ=30/6=5
Answer:
2.00 N
Explanation:
Weight is mass times gravity:
W = mg
Mass is density times volume:
m = ρV
Volume of a cylinder is:
V = πr²h
Finding the volume:
V = π (2.00 cm)² (6.00 cm)
V = 75.4 cm³
The density of aluminum is 2.7 g/cm³. Finding the mass:
m = (2.7 g/cm³) (75.4 cm³)
m = 204 g
Finding the weight:
W = (0.204 kg) (9.8 m/s²)
W = 2.00 N
The aluminum cylinder weighs 2.00 N.