Answer:
Mass can never be negative. Everything has mass. Just like how they ask you to find area under the graph in maths. If the area is in the 3rd and 4th quadrant, when calculated, you would get negative answer.However, area can not be negative because it is a place/ location. It's exactly the same as mass.
1km=10^3 m,1km^3=10^9cubic metres answer is 1.4x10^18cubic meters
To solve this problem it is necessary to apply the law of Malus which describes the change in the Intensity of Light when it crosses a polarized surface.
Mathematically the expression is given as

Where,
= Initial Intensity
I = Final Intensity after pass through the polarizer
= Angle between the polarizer and the light
Since it is sought to reduce the intensity by half the relationship between the two intensities will be given as

Using the Malus Law we have,





Angle with respect to maximum is 
Answer:
Explanation:
There will be loss of potential energy due to loss of height and gain of kinetic energy .
loss of height = R - R cos 14 , R is radius of hemisphere .
R ( 1 - cos 12 )
= 13 ( 1 - .978 )
h = .286 m
loss of potential energy
= mgh
= m x 9.8 x .286
= 2.8 m
gain of kinetic energy
1/2 m v ² = mgh
v² = 2 g h
v² = 2 x 9.8 x 2.8
v = 7.40 m /s
Answer:
The tube should be held vertically and perpendicular to the ground.
Explanation:
Answer: The tube should be held vertically and perpendicular to the ground. The reason is as follows:
Reasoning:
The power lines are parallel to the ground hence, their electric field will be perpendicular to the ground and equipotential surface will be cylindrical.
Hence, if you will put fluorescent tube parallel to the ground then both the ends of the tube will lie on the same equipotential surface and the potential difference will be zero.
So, to maximize the potential the ends of the tube must be on different equipotential surfaces. The surface which is near to the power line has high potential value and the surface which is farther from the line has lower potential value.
hence, to maximize the potential difference, the tube must be placed perpendicular to the ground.