Answer: MR²
is the the moment of inertia of a hoop of radius R and mass M with respect to an axis perpendicular to the hoop and passing through its center
Explanation:
Since in the hoop , all mass elements are situated at the same distance from the centre , the following expression for the moment of inertia can be written as follows.
I = ∫ r² dm
= R²∫ dm
MR²
where M is total mass and R is radius of the hoop .
Answer:
100 cc
Explanation:
Heat released in cooling human body by t degree
= mass of the body x specific heat of the body x t
Substituting the data given
Heat released by the body
= 70 x 3480 x 1
= 243600 J
Mass of water to be evaporated
= 243600 / latent heat of vaporization of water
= 243600 / 2420000
= .1 kg
= 100 g
volume of water
= mass / density
= 100 / 1
100 cc
1 / 10 litres.
Answer:
Cosmic ray's frame of reference: 99,875 years
Stationary frame of reference: 501,891 years
Explanation:
First of all, we convert the distance from parsec into metres:

The speed of the cosmic ray is

where
is the speed of light. Substituting,

And so, the time taken to complete the journey in the cosmic's ray frame of reference (called proper time) is:

Converting into years,

Instead, the time elapsed in the stationary frame of reference is given by Lorentz transformation:

And substituting v = 0.98c, we find:

Answer:
-2
Explanation:
Since its a compound, it's charge is 0.
So, there are 2 Fe and 3 Oxygen,
let x = oxidation number of oxygen
2(+3) + 3x =0
x =-2
Side note : even if the oxidation number is positive, make sure to put the positive sign like how you would in numbers
Answer:
Explanation:
It is a case of oscillation by simple pendulum . Expression for simple pendulum is given as follows
T = 
where T is time period , l is length of pendulum and g is acceleration due to gravity .
, f is frequency of oscillation
For the given case

subsequently length becomes half so

dividing

f = 
frequency of oscillation becomes √2 times.