Answer:
infra red radiation is used
Answer:
4. Electrons move from higher energy states to lower energy states.
Explanation:
When electrons fall from a higher (excited) energy state to a lower energy state, it loses/gives out energy.
This energy is given out by the emission of photons (quanta of light) by the electron.
Answer:
Explanation:
Speed of skier without parachute
= √ 2gh
= √ 2 x 9.8 x 35
= 26.2 m / s
Speed of skier with parachute
net force downwards
mg - 200
= 60 x 9.8 -200
= 388 N
acceleration = 388 / 60
a = 6.47 m / s
v = √ 2ah
= √ 2 x 6.47 x 35
= 21.28 m / s
Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:
where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,
Now, we will calculate the number of uranium nuclei left (
):
and the rest of the uranium nuclei will become thorium nuclei (
)
dividing both:
<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>
