Density is mass divided by volume. rho=m/v. So, v=m/rho. In frank's case this is 80/8 = 10 cm^3.
Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:

Where
corresponds to Plank constant (6.626070x10^-34Js),
is the speed of light in the vacuum (299792458m/s) and
is the wavelength of the photon(in this case 800nm).

Tranform the units

The band Gap is 4eV, divide the band gap between the energy of the photon:

Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.
Answer:
d=0.137 m ⇒13.7 cm
Explanation:
Given data
m (Mass)=3.0 kg
α(incline) =34°
Spring Constant (force constant)=120 N/m
d (distance)=?
Solution
F=mg
F=(3.0)(9.8)
F=29.4 N
As we also know that
Force parallel to the incline=FSinα
F=29.4×Sin(34)
F=16.44 N
d(distance)=F/Spring Constant
d(distance)=16.44/120
d(distance)=0.137 m ⇒13.7 cm
the state of being thick, sticky, and semifluid in consistency, due to internal friction.