Answer: 9x10-3ms-1 -- A
Explanation:
Given wavelength λ = 505nm
1nm= 10^9m
505nm = 5.05 x10 ^-7m
and speed of light, c is 3.8 x 10^ 8
frequency = ?
Using frequency = speed of light / wavelength
f = c/λ
Frequency , f= 3.8 x10^8m/s/ 5.05 x10 ^-7m
=5.94 x 10 ^14 s⁻1
Also Energy = hv
where h =Planck constant = 6.626 x10 ^ -34 J.s
v= frequency =5.94 x 10 ^14 s⁻1
Energy = 6.636 x10 ^ -34 J.s x5.94 x 10 ^14 s⁻1
= 3.935 x 10 ^-19J
Given
9.5×10 −12 g as the mass of the bacterium,
changing to kg
1000g= 1kg
9.5×10 −12 g = 9.5×10 −15kg
to find the velocity
Energy = 1/2mv² = E=1/2mv²
v= =
v =0.009099= 9x10-3ms-1