Answer:
k = 3.5 N/m
Explanation:
It is given that the time period the bob in pendulum is the same as its time period in spring mass system:


where,
k = spring constant = ?
g = acceleration due to gravity = 9.81 m/s²
m = mass of bob = 125 g = 0.125 kg
l = length of pendulum = 35 cm = 0.35 m
Therefore,

<u>k = 3.5 N/m</u>
I think frequency it sounds like the correct answer but I am not completely sure if I am correct
Answer:
As you know, the denser objects have more weight per unit of volume, this will mean that the force that pulls down these objects is a bit larger.
This will mean that the denser objects will always go to the bottom.
This clearly implies that the red liquid, the one with one of the smaller densities, can not be at the bottom.
There are some cases where a liquid with a small density may become a lot denser as the temperature or pressure changes, and in a case like that, we could see the red liquid at the bottom, but for this case, there is no mention of changes in the temperature nor in the pressure, so this can be discarded.
The only thing that makes sense is that the red part at the bottom is the base of the tube, and has nothing to do with the red liquid.
Answer: The person will still have a mass of 90kg on Mars
Explanation: The Truth is, the mass of a body remains constant from place to place. It is the weight which is equal to {mass of body * acceleration due to gravity{g}} that varies from place to place since it is dependent on {g}.
In this case the person will have a Weight of 90*9.8 = 882N on Earth.
{ "g" on Earth is 9.8m/s²}
And a Weight of 90*3.3 = 297N on Mars.
{ From the question "g" on Mars is {9.8m/s²}/3 which is 3.3m/s²}
From this analysis you notice that the WEIGHT of the person Varies but the MASS remained Constant at 90kg.
The refractive index for glycerine is

, while for air it is

.
When the light travels from a medium with greater refractive index to a medium with lower refractive index, there is a critical angle over which there is no refraction, but all the light is reflected. This critical angle is given by:

where n1 and n2 are the refractive indices of the two mediums. If we susbtitute the refractive index of glycerine and air in the formula, we find the critical angle for this case: