Answer:
8.61 min
Explanation:
original mass= 12.65
first half life = 12.65/2 = 6.325
second half life = 6.325/2 = 3.1625
Note : 3.1625 is the closest to the value (3.115) given so we work with it
total time for decay =17.22
therefore two decays = 17.22/2= 8.61
Answer:9.34 A/s
Explanation:
Given
radius of solenoid 
Emf induced 
no of turns per meter n=450
we know Induced EMF is given by

Magnetic Field is given by

thus 
Area of cross-section
where
solving integration we get

where r=distance from axis
R=radius of Solenoid



Explanation:
Below is an attachment containing the solution.
Explanation:
Mirrors consist of reflecting surfaces that reflect light.
Reflection is a phenomenon of light wave (but also of other types of waves) in which a ray of light hits a surface, and then it bounces back into the original medium at a certain angle.
The direction of the reflected ray is determined by the law of reflection:
- The incident ray, the reflected ray and the normal to the surface all lie in the same plane
- The angle of reflection is equal to the angle of incidence (where both angles are measured between the ray and the normal to the surface)
A plane mirror is a type of mirror consisting of a straight surface. As a result, light incident perpendicular to the surface is reflected back exactly in the opposite direction.
The image formed by a plane mirror is:
- The same size as the object
- Virtual (it is located behind the mirror)
- Laterally inverted
- Upright