To solve this problem we will apply the concepts related to the balance of forces. Said balance will be given between buoyancy force and weight, both described as derived from Newton's second law, are given as
Buoyancy force

Here,
V = Volume
=Density of air
g = Acceleration due to gravity
Weight

m = mass
g = Gravity
Our values are given as,




Then,

Replacing,

Now net force is ,

Mass of the sphere is

Now acceleration of the sphere is



Therefore the acceleration of the sphere as it falls through water is 
Answer:
Frequency is 
Explanation:
Distance between source 1 from the receiver , 
Distance between source 2 from the receiver , 
Now ,
Path difference , 
We know, for constructive interference path difference should be integral multiple of wavelength .
Therefore, 
It is given that n = 1,
Therefore, 
Frequency can be found by , 
Hence, this is the required solution.
Using the Definition of Kinetic Energy, we have:
Answer:
Explanation:
Since the surface is frictionless therefore there will be no friction force on block but there will be weight of block which we can divide in to two components i.e. mgcosθ &mgsinθ which is perpendicular and parallel to the surface respectively.
In response to mgcosθ ramp will apply a normal force to the block which will be of equal magnitude to that of mgcosθ.
Therefore Ramp will apply a Force of mgcosθ on block where m is the mass of block.
The answer is C but man if you have leak or a meltdown good luck to anyone downstream.