-- make sure you have enough money;
-- make sure you arranged for someone to feed the dog and the goldfish;
-- make sure you turned off the faucets and the stove burners.
Answer:
support lights as a wave
Explanation:
In the model of light as a particle, the experimenter would expect to see one small hole of light emerging on the wall. However, as the light spreads out, it behaves much like a wave that diffracts when going through a small hole.
Answer:
500 nm
Explanation:
= Distance traveled by light from left slit
= Distance traveled by light from right slit
= Path difference = 
m = Order = 1
= Wavelength = 550 nm
Path difference is given by

The required distance is 500 nm
Answer:
The velocity of the police car is, v = 17.798 m/s
Explanation:
Given data,
The actual frequency of the siren, f = 2010 Hz
The observed frequency of siren is, f' = 2120 Hz
The velocity of the observer, v' = 0 m/s
The velocity of the source, v = ?
The formula for Doppler effect,

Where,
V - velocity of sound waves in air.

Substituting the given values,

v = 17.798 m/s
Hence, the velocity of the police car is, v = 17.798 m/s
Can you elaborate more on the question please