Final velocity = 0, thus final kinetic energy is 0
Initial kinetic energy:
0.5mv²
= 0.5 x 0.48 x 4.08²
= 4.0 J
Decrease in kinetic energy = 4 - 0 = 4 Joules
Answer:
V = 0.0806 m/s
Explanation:
given data
mass quarterback = 80 kg
mass football = 0.43 kg
velocity = 15 m/s
solution
we consider here momentum conservation is in horizontal direction.
so that here no initial momentum of the quarterback
so that final momentum of the system will be 0
so we can say
M(quarterback) × V = m(football) × v (football) ........................1
put here value we get
80 × V = 0.43 × 15
V = 0.0806 m/s
Answer:
Light of a shorter wavelength should be used.
Explanation:
This is studied in the phenomenon called photoelectric effect, in which light is able to release electrons from a metal, said electrons are called photoelectrons .
The experiments that have been carried out show that <u>increasing or decreasing the intensity of the light will not cause the photoelectrons to be emitted</u>, what will cause the photoelectrons to be emitted is to increase the frequency of the incident light.
And a higher frequency corresponds to a shorter wavelength according to the equation:

(where
is frequency,
the speed of light, and
the wavelength)
So the answer is that the wavelength of the light must be shortened to cause the emission of electrones.