Answer:
1065 Kgm-3
Explanation:
We can determine the relative density of the athlete from the formula;
Relative density of athlete = weight of athlete in air/upthrust on athlete
Since weight of athlete in air= 690 N
Weight of athlete in water = 42 N
Upthrust on athlete= weight in air - weight in water
Upthrust on athlete= 690 N - 42 N = 648 N
Relative density of athlete= 690 N / 648 N
Relative density of athlete= 1.065
Therefore, average density of the athlete= relative density × density of water = 1.065 × 1000 Kgm-3 = 1065 Kgm-3
Answer:
40J
Explanation:
Kinetic energy = 1/2 mv^2
Where m = mass and
v = velocity
Given mass = 20kg
v = 2m/s
K.E = 1/2 x 20 x2^2
= 1/2 x 20 x 2 x 2
= 80/2
= 40J
Answer:
7407.4 units
Explanation:
m(t) = m(0) e^kt
Here, k = - 0.000135
So, the above equation becomes
m(t) = m(0) e^(-0.000135 t)
Compare with the standard equation of radioactivity
m(t) = m(0) e^-λt
Where, λ be the decay constant
So. λ = 0.000135
The relation between the decay constant and the mean life is
ζ = 1 / λ
Where, ζ is the mean life
So, ζ = 1 / 0.000135 = 7407.4 units
The effect that is seen is that the brightness of the bulb is unaffected by switching the polarity of the magnet; however, the order in which the needle deflects on the voltmeter is flipped when you do so.
This is further explained below.
<h3>What is switching the polarity?</h3>
Generally, When the polarity is reversed, both the hot wire and the neutral wire are switched, which causes the electric current to flow in the opposite direction. Because of this, the electric current enters the appliance through the neutral terminal rather than the hot terminal, which energizes the appliance even when it is turned off.
In a worst-case scenario, the battery's shell might burst apart due to the heat generated by the polarity reversal, which would release hydrogen gas, which is flammable. Acid from the battery may leak out of the box and burn you or damage your expensive electronics.
In conclusion, In this case, reversing the magnet's polarity has no impact on the light output of the bulb, but it does reverse the direction of the voltmeter's needle deflection.
Read more about switching the polarity
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