A beta particle. Hoped I help. Sorry if it wrong.
Answer:
D) 763 nm
Explanation:
Calculation for the wavelength of light
Using this formula
Wavelength of light=Delta Y*Distance / Length
Where,
Delta Y represent the 2nd order bright fringe
Length represent the distance between both the slits and the screen
Distance represent the Distance between the slits
Let note that cm to m = (4.2) x 10^-2 and mm to m= ( 0.0400x 10^-3)
Now Let plug in the formula
Wavelength of light=[(4.2 x 10^-2m)(0.0400 x 10^-3m) / 2(1.1m)]*10^-7 meters
Wavelength of light=[(0.042m) (0.0004m)/2.2m]*10^-7 meters
Wavelength of light =(0.0000168m/2.2m)*10^-7 meters
Wavelength of light =7.63 *10^-7 meters
Wavelength of light =763 nm
Therefore the Wavelength of light will be 763 nm
Answer:

Explanation:
Since the hoop is rolling on the floor so its total kinetic energy is given as

now for pure rolling condition we will have

also we have

now we will have


now by work energy theorem we can say



now solve for final speed

Answer:
It is because it is a unit of Power(which is a derived quantity)