Explanation:
Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum.
The text does not specify whether the resistance R of the wire must be kept the same or not: here I assume R must be kept the same.
The relationship between the resistance and the resistivity of a wire is

where

is the resistivity
A is the cross-sectional area
R is the resistance
L is the wire length
the cross-sectional area is given by

where r is the radius of the wire. Substituting in the previous equation ,we find

For the new wire, the length L is kept the same (L'=L) while the radius is doubled (r'=2r), so the new resistivity is

Therefore, the new resistivity must be 4 times the original one.
Answer:1.04 N
Explanation:
Given
Gravitational Force on the Platter is 
Tray makes an angle of 
This gravitational Force has components along and Perpendicular to Platter
Perpendicular Force 

Along the Tray


Thus 1.04 N is the magnitude of force that will cause Platter to slide down
Assuming that reaching a height 0 doesn’t stop the ball, and that it accelerates at 9.8 m/s^2, the ball would be traveling at 0.5 + 0.7*9.8 = 7.36 m/s downwards.
Answer:

Solution:
As per the question:
Mass of first object, m = 120 kg
Mass of second object, m' = 420 kg
Mass of the third object, M = 69.0 kg
Distance between the m and m', d = 0.380 m
Now,
To calculate the gravitational force on the object of mass, M placed mid-way due to mass, m:
To calculate the gravitational force on the object of mass, M placed mid-way due to mass, m':
To calculate the gravitational force on the object of mass, M placed mid-way due to mass, m and m':

