Answer : The number of half-life periods will be, 3
Explanation : Given,
Initial amount of lead = 10 kg
Amount of lead after decay = 1.25 kg
Half-life = 22 years
Formula used :
where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives
= half-life
Now put all the given values in the above formula, we get:
Thus, the number of half-life periods will be, 3
Take the moment car A starts to accelerate to be the origin. Then car A has position at time <em>t</em>
<em>x</em> = (20.0 m/s) <em>t</em> + 1/2 (2.10 m/s²) <em>t</em>²
and car B's position is given by
<em>x</em> = 300 m + (27.0 m/s) <em>t</em>
<em />
Car A overtakes car B at the moment their positions are equal:
(20.0 m/s) <em>t</em> + 1/2 (2.10 m/s²) <em>t</em>² = 300 m + (27.0 m/s) <em>t</em>
300 m + (7.00 m/s) <em>t</em> - (1.05 m/s²) <em>t</em>² = 0
==> <em>t</em> ≈ 20.6 s
If we neglet air resistance for both objects then both will fall parallely(at same time) because time taken by both objects is independent of mass. there is famous experiment i.e"feather coin experiment" . normally we think that heaver objects falls faster but this is wrong concept. it depends on medium in which objects are moving.
thanku
Answer:
Option C. The force between them would be 4 times larger than with the
initial masses.
Explanation:
To know which option is correct, we shall determine the force of attraction between the two masses when their masses are doubled. This can be obtained as follow:
From:
F = GMₐM₆/ r²
Keeping G/r² constant, we have
F₁ = MₐM₆
Let the initial mass of both objects to be m
F₁ = MₐM₆
F₁ = m × m
F₁ = m²
Next, let the masses of both objects doubles i.e 2m
F₂ = MₐM₆
F₂ = 2m × 2m
F₂ = 4m²
Compare the initial and final force
Initial force (F₁) = m²
Final (F₂) = 4m²
F₂ / F₁ = 4m² / m²
F₂ / F₁ = 4
F₂ = 4F₁ = 4m²
From the above illustrations, we can see that when the mass of both objects doubles, the force between them would be 4 times larger than with the
initial masses.
Thus, option C gives the correct answer to the question.
W=2485.65 J ,work did the movers do friction force a 41.0- kg crate 10.3 m across a rough floor without acceleration
<h3>What is a basic friction force?</h3>
Two surfaces that come into contact and slide against one another produce a force known as frictional force. Several aspects that influence the frictional force include: The surface texture as well as the amount of force attracting them together have the most effects on these forces.
<h3>What outcomes does friction produce?</h3>
It generates heat, which is useful for warming our bodies or specific areas of any object. Power is also lost as a result. It makes noise during every operation. We are able to walk, run, dance, etc. due to friction.
To know more about friction force visit:
brainly.com/question/1389727
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