This is the upthrust on an object which is placed inside a fluid
This force act upwards and always push upwards
so the correct answer is given as
D. A force within a fluid that pushes upward
this force is always due to pressure difference at two levels of
at lower level since pressure is more that is why the force is upwards and this upthrust is known as Buoyancy
Answer:

Explanation:
Given that there are two force of 1 pound each at right angles to each other.
The from the vector law of addition:

where:
resultant force
be the two of the forces to be added.


Change of a liquid to a gas
Efficiency η of a Carnot engine is defined to be:
<span>η = 1 - Tc / Th = (Th - Tc) / Th </span>
<span>where </span>
<span>Tc is the absolute temperature of the cold reservoir, and </span>
<span>Th is the absolute temperature of the hot reservoir. </span>
<span>In this case, given is η=22% and Th - Tc = 75K </span>
<span>Notice that although temperature difference is given in °C it has same numerical value in Kelvins because magnitude of the degree Celsius is exactly equal to that of the Kelvin (the difference between two scales is only in their starting points). </span>
<span>Th = (Th - Tc) / η </span>
<span>Th = 75 / 0.22 = 341 K (rounded to closest number) </span>
<span>Tc = Th - 75 = 266 K </span>
<span>Lower temperature is Tc = 266 K </span>
<span>Higher temperature is Th = 341 K</span>
Answer:
Explanation:
fringe separation or fringe width is directly proportional to wavelength .
Δ₁ / Δ₂ = wave length of first laser / wavelength of second laser
Δ₁ is fringe separation in first case and Δ₂ is fringe separation in second case.
putting the given values
632.8 / wavelength of second laser = 4.5 / 4.64
wavelength of second laser = 632.8 x (4.64 / 4.5)
= 652.48 nm
652 nm