Two tiny spheres of mass m = 3.00 mg carry charges of equal magnitude, 72.0nC, but opposite sign. They are tied to the same ceiling hook by light strings of length 0.530m. When a horizontal uniform electric field E that is directed to the left is turned on, the spheres hang at rest with the angle θ between the strings equal to 50.0 degrees in the figure below. What's the magnitude E of the field and which ball (left or right) has a positive charge?

i guess it’s a and b

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.

3. dark matter

empty space could also be a simple vacuum