"Frequency" just means "often-ness" ... how often something happens.
It's always expressed as
<em>(number of happenings) / (some period of time) .</em>
Answer:
The wavelength of the light is
.
Explanation:
Given that,
Distance between the slit centers d= 1.2 mm
Distance between constructive fringes 
Distance between fringe and screen D= 5 m
We need to calculate the wavelength
Using formula of width

Put the value into the formula




Hence, The wavelength of the light is
.
Assume a maximum stopping acceleration of g/2 where g is acceleration due to gravity.
Answer:
2.99 m/s
Explanation:
Stopping distance, s = 3 ft = 0.914 m
final velocity, v = 0
a = g/2 = 4.9 m/s²
Use third equation of motion:

substitute the values to find the speed of train:

Answer:
3.98V
Explanation:
Given
Pontential difference V as 3v
Energy delivered is 30%,
Recall that Enery E=1/2cv^2 from this E=V^2(since Current C is not provided we can assume a value 2)
So E=V^2
E=3^2=9
At full charge E=9,30%of 9,0.3*9=2.7 energy in capacitor is 9-2.7=6.3
But E=V^2
✓E=V
✓6.3=3.98V