D. A bargain hunter purchases a "gold" crown at a flea market. After she gets home, she hangs it from a scale and finds its weig
ht to be 7.84 N. She then weighs the crown while it is immersed in water, and now the scale reads 6.86 N. Is the crown made of pure gold? Find the density of the crown and compare it to the it to density of the gold.
When a negative point charge is placed at x=0 and an electron is place at any point P on the positive x-axis the as we know that the like charges repel each other, but there will be no change in the natural tendency of the individual electric field lines.
So the direction of the electric field lines at point P due to the point charge will be towards the negative x-axis.
The direction of force on the electron due to the electric field of point charge at x=0 will be towards positive x-axis in accordance of the repulsion effect.