Explanation:
Through the uranium-lead dating, you can establish the age of rocks that formed from 1 million years ago to 4.5 billion years with enough precision. Dating meteorites using this method, It is possible to establish the age of the earth, since these are pieces that are present since the formation of the solar system, so they are approximately the same age as the Earth.
Answer:
38.6 N
2.57 m/s²
Explanation:
Draw a free body diagram of the box. There are four forces:
Weight force mg pulling down,
Normal force N pushing up,
Friction force Nμ pushing left,
and applied force P pulling at an angle 40°.
Sum of forces in the y direction:
∑F = ma
N + P sin 40° − mg = 0
N = mg − P sin 40°
The net force in the x direction is:
∑F = P cos 40° − Nμ
∑F = P cos 40° − (mg − P sin 40°) μ
∑F = P cos 40° − mgμ + Pμ sin 40°
∑F = P (cos 40° + μ sin 40°) − mgμ
Plugging in values:
∑F = (80 N) (cos 40° + 0.23 sin 40°) − (15 kg) (10 m/s²) (0.23)
∑F = 38.6 N
Net force equals mass times acceleration:
∑F = ma
38.6 N = (15 kg) a
a = 2.57 m/s²
Classical physics considered light to behave as a wave in all environments; it had a set amplitude, frequency etc. The problem was that this meant that there was a continuous variation in its properties, hence if the amplitude of the light was incresed by a bit, a phenomenon like the phhotoelectric one would become only marginally more apparent. However, in this case, there is a cutoff point which means that the only-wave theory had to be wrong.
The sound waves travel because of the pitch of the note so the window rattles.
Answer:

Explanation:
We have given mass m=0.155 kg
Force constant K = 305 N/m
Distance 
Velocity 
The total energy at any position of the motion is give by
here
is energy due to motion and
is energy due to spring elongation
So total energy 