Answer:
The initial velocity is 50 m/s.
(C) is correct option.
Explanation:
Given that,
Time = 10 sec
For first half,
We need to calculate the height
Using equation of motion

....(I)
For second half,
We need to calculate the time
Using equation of motion



Put the value of h from equation (I)


According to question,


Put the value of t₁ and t₂



Here, g = 10
The initial velocity is


Hence, The initial velocity is 50 m/s.
The radius of the cylinder is equal to half the diameter:

The volume of the cylinder is given by:

where h is the heigth of the cylinder. Converting into meters,

And the density of the material will be given by the ratio between the mass and the volume:

Answer:
c. The temperature at which a glass transforms from a solid to liquid.
Explanation:
The glass transition temperature is said to be a temperature range when a polymer structure transition from a glass or hardy(solid) material to a rubber like or viscous liquid material.
The glass transition temperature is an important property that is critical in product design.
Answer:
Approximately 1.62 × 10⁻⁴ V.
Explanation:
The average EMF in the coil is equal to
,
Why does this formula work?
By Faraday's Law of Induction, the EMF
induced in a coil (one loop) is equal to the rate of change in the magnetic flux
through the coil.
.
Finding the average EMF in the coil is similar to finding the average velocity.
.
However, by the Fundamental Theorem of Calculus, integration reverts the action of differentiation. That is:
.
Hence the equation
.
Note that information about the constant term in the original function will be lost. However, since this integral is a definite one, the constant term in
won't matter.
Apply this formula to this question. Note that
, the magnetic flux through the coil, can be calculated with the equation
.
For this question,
is the strength of the magnetic field.
is the area of the coil.
is the number of loops in the coil.
is the angle between the field lines and the coil. - At
, the field lines are parallel to the coil,
. - At
, the field lines are perpendicular to the coil,
.
Initial flux:
.
Final flux:
.
Average EMF, which is the same as the average rate of change in flux:
.
On Earth, gravity adds 9.8 m/s to the downwsrd speed of any falling object, every second. Beginning from zero downward speed, the speed grows to (8 x 9.8) = 78.4 m/s downward after 8 sec.