Why physics is difficult

Especially in Electromagnetism...​

Asmall 12.00g plastic ball is suspended by a string in a uniform, horizontal electric field with a magnitude of 10^3 n/c. if the ball is in equilibrium when the string makes a 30 ° angle with the vertical, what is the net charge on the ball?

Which statements did both aristotle and ptolemy assume? check all that apply.

Water flows through a garden hose which is attached to a nozzle. the water flows through hose with a speed of 2.19 m/s and through the nozzle with a speed of 19.8 m/s. calculate the maximum height (in m) to which water could be squirted if it emerges from the nozzle and emerges with the nozzle removed.