Answer:
This is because the force of gravity is much less on the moon than on the earth, therefore the person wont be pulled down much and will jump higher
Answer:
Explanation:
Both are contact forces arising at the interface between two bodies. In the fluid this interface might be irregular, and it completely surrounds a submerged object. For a solid it is usually a single flat surface - but it can be a collection of surfaces, which do not need to be flat or regular, and which can surround the object
Upthrust occurs at a fluid-solid interface whereas normal reaction occurs at a solid-solid surface. However, it is possible to generate the same fluid-like phenomenon of upthrust by immersing a solid object in sand or small beads and agitating them to simulate the pressure of atoms. With
Answer:
- 0.09 % of the original radioactive nucllde its left after 10 half-lives
- It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Explanation:
The equation for radioactive decay its:
,
where N(t) its quantity of material at time t,
its the initial quantity of material and
its the mean lifetime of the radioactive element.
The half-life
its the time at which the quantity of material its the half of the initial value, so, we can find:

so:




So, after 10 half-lives, we got:




So, we got that a 0.09 % of the original radioactive nucllde its left.
Putonioum-239 has a half-life of 24,110 years. So, 10 half-life will take to pass

It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Answer:
1.73 seconds
Explanation:
The velocity the ball first hits the ground with is:
v² = v₀² + 2aΔx
v² = (0 m/s)² + 2 (-10 m/s²) (-20 m)
v = -20 m/s
The velocity it rebounds with is 3/4 of that in the opposite direction, or 15 m/s.
The time it takes to return to the ground is:
Δx = v₀ t + ½ at²
0 = (15 m/s) t + ½ (-10 m/s²) t²
0 = t (15 − 5t²)
t = √3
t ≈ 1.73 seconds
Answer:
A magnets always have two poles (north and south), the unmagnetized rod can be identified using properties of the poles of a magnet.
Explanation:
The law of magnetism states that like poles repel, while unlike poles attract. The simple experiment here is to use two rods at a time, keeping one of the poles of the first rod constant, while changing the poles of the other rod.
When the two rods are magnets, attraction and repulsion would be observed between the rods. But for the case of unmagnetized rod and one of the magnetised rod, only attraction is observed between the poles.