The si unit of force is newton.
so, F is eqal to m*g
If the object has a lower density it will float and it if it has a higher density it will sink, different liquids may also be heavier or lighter causing a different outcome.
In optics, a diffraction grating is an optical component with a periodic structure, which splits and diffracts light into several beams travelling in different directions.
Answer:
"The distance between crests is 3 cm."
Explanation:
If he writes down "The distance between crests is 3 cm."
That means he is describing the wavelength of a wave and not longitudinal wave. He ought to write something about " direction "
Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or parallel to, the direction of propagation of the wave. While
Wavelength is the distance between the two successfully Crest or trough
Answer:
The temperature of cold reservoir should be 246.818 K for efficiency of 35%
Explanation:
In first case we have given efficiency of Carnot engine = 26 % = 0.26
Temperature of cold reservoir 
We know that efficiency of Carnot engine is given by



For second Carnot engine efficiency is given as 35% = 0.35
And temperature of hot reservoir is same so 
So 

So the temperature of cold reservoir should be 246.818 K for efficiency of 35%