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>
Answer: Option (B)
Explanation: A stream transports its materials in different ways-
- <u>Dissolved load-</u> Here, the materials gets dissolved when mixed with water and flows along with the stream.
- <u>Suspended load</u>- Here, the materials are not fully dissolved in the water but they can be carried from one place to another in suspension mode, by the river.
- <u>Bed load-</u> Bed load are transported in three different ways such as-
- Sliding- here, the materials slides down along a curved surface under the water and carried away.
- Rolling- here, the materials are solid and due to force exerted by water, it can roll and move to distant places.
- Saltation- here, the materials are carried away in a series of jumps.
Thus, the most appropriate answer is option (B) i.e bedload.
Heat absorbed by the solar collector = Area*Irradiance = 5.3*995 = 5273.5 W
Heat Q in joules absorbed in t hours = Heat used to heat water. That is,
5273.5*t = mCΔT; where mass = volume*density = 1*1000 = 1000 kg
Therefore;
5273.5t = 1000*4186*(65-20) = 188370000
t = 188370000/5273.5 = 35720.11 seconds = 35720.11/(60*60) hours ≈ 9.92 hours.
It will take approximately 9.92 hours.
Answer:
Newton's third law of motion.
Explanation:
An ice skater at rest pushes against a sled at rest,causing both the skater and sled to move away from each other with different acceleration. It is based on Newton's third law of motion.
Third law says that, for every action there is an equal; and opposite reaction. Here, action is force applied by ice skater and reaction is motion of skater and sled away from each other with different acceleration.
