Which statement best defines an electric field?
O A. force per unit charge on a negative source charge
B. force per unit charge on a negative test charge
OC. force per unit charge on a positive source charge
D. force per unit charge on a positive test charge

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).

Aball horizontally thrown from a cliff at 8m/s