When a balloon is rubbed with a wool cloth, e<span>lectrons move from the atoms in the balloon to the atoms in the cloth, causing the cloth to have a negative charge. Therefore, the answer is B. Before they were rubbed together, they both had balanced charges. However, after rubbing them, the wool is left with the positive charge, and the balloon with the negative. This causes the atoms in the cloth to flow to the balloon, leaving the cloth with a negative charge.</span>
They will use pulleys or something with a wheel and axle
at t=T/6, total distance covered= 2*pi*r/6 and displacement= r
difference of them = 2*t
so, 2*pi*r/6- r =2(1/6)=1/3
r=1/(pi-3)=7.062
Answer:
b) The light slows down and it changes direction towards the perpendicular.
Explanation:
Light travels at different speed in different mediums.
Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.
Or ,
n = c/v.
Light travels at a slower speed in water as compared to air because there are more number of interfering molecules in the path of the light in case of water as compared to liquid.
<u>When a light travels from lower denser medium say water to higher denser medium say water, it bends towards the perpendicular as its speed reduces in that medium.</u>
