Mr. Roentgen's x-rays allowed scientists to measure the size of the atom. The x-rays were small enough to discern the atomic clouds. This was done by scattering x-rays from atoms and measuring their size just as Rutherford had done earlier by hitting atoms with other nuclei starting with alpha particles.
Answer:
601 nm
Explanation:
Energy of photon having wavelength of λ nm
=
eV
Energy of 249 nm photon
=
=4.996 eV
Similarly energy of 425nm photon
=
=2.927 eV
Difference = 2.069 eV.
This energy will give rise to another photon whose wavelength will be
λ = 
= 601 nm.
Divide the distance by the speed:
(18 m) / (42 m/s) = 3/7 s ≈ 0.43 s
Answer:

Explanation:
We are given that
Radius,r=2 m
Moment of inertia,I=250
Angular velocity,
Mass of child,m=20 kg
We have to find the new moment of inertia of the merry go round.
New moment of inertia ,
Using the formula


Hence, the new moment of inertia of the merry -go-round=