<h2>Answer:</h2>
The option C is the correct answer.
Which is, "He varies the nitrogen and carbon dioxide levels in the air from one trial to the next".
<h3>Explanation:</h3>
The hypothesis of Malik was about the effect of increased oxygen level on the growth of the red-legged grasshoppers.
So the areas of his experiment should be the:
- Grasshopper type.
- High oxygen level.
- Rate of growth of grasshopper.
So all the given options are relevant to his experiment except the third one.
So varying the nitrogen and carbon dioxide level in air could not contribute in his experiment.
<h2 />
Answer:
Explanation:
We shall apply concept of impulse
Impulse = Force x time
= Force x 2 x 10⁻³ N.s
impulse = change in momentum
change in momentum
= .4 x 4 - ( - .4 x 2 )
= 2.4
Force x 2 x 10⁻³ = 2.4
Force = 2.4 / 2 x 10⁻³
= 1.2 x 10³ N .
average magnitude of the force exerted by floor = 1.2 x 10³ N
If R be reaction force by earth
R - mg = 1.2 x 10³
R = 1.2 x 10³ + mg
= 1200 + .4 x 9.8
= 1200 +3.92
= 1203 .92 N .
The answer would be it will be longer than the 656.3 nm. The reduced mass of positronium is less than hydrogen so the photon energy will be a reduced amount of for positronium than for hydrogen. So this will mean that the wavelength will be lengthier.
Answer: d)
Explanation: In order to justify the answer we have to consider that the energy of photons directely depent on the frequency so the energy is inverselly dependent of the wavelegth.
If both beams have the same power, this means Energy/time so the number of photons per second must be different. As consequence a) is wrong as b) since it is not posible since UV photon have more energy that IR photons. c) It is no necessary know the frequency since the wavelength is related in the form:
c=λν c is the speed of light, λ the wavelegth and ν the frequency.
d) Certainly will be more more IR photons than UV photons to get the same beam power.
