# 7 short questions on physics need to be answered ( I need it in 30 min ) OAS

1- Scuffing your feet across a carpet on a cold dry day, you pick up 47,010,000,000 electrons.  How much charge is that, in microcoulombs (uC)?

2- A hollow metal sphere of radius 12.7 cm carries a charge of 2.47 uC.  What is the electric field strength, E, in N/C on its surface?  Use "E" notation for your answer.

3- A hollow metal sphere of radius 12.5 cm carries a charge of 1.2  uC.  What is the electric field strength, E, anywhere inside it?

4- A hollow metal sphere of radius 8.7 cm carries a charge 0.34 uC.  What is the electric field strength, E, in N/C at a point a distance 11.5 cm away from its surface?   Use "E" notation for your answer.

5- Protons carry a charge of +1.6e-19 C.  If the repulsive force between two protons in an atomic nucleus equals 84 N, how far apart are the protons, in picometers (that's trillionths of a meter)?   Use "E" notation for your answer.

6- A company called Illinois Capacitor sells an amazing device, a 100 F capacitor with a peak voltage of 2.7 V.  It is only about an inch across and less than two inches high.  How much energy, in J, can it hold in its internal electric field?  Enter your answer to two significant figures.

7- In a hydrogen atom, an electron with a charge of (-)1.6E-19 orbits a proton with the same but positive charge at a distance 65 picometers away (that's trillionths of a meter or 10-12 m).  What electric force F, in N, binds the two particles together?   Use "E" notation for your answer.

• Posted: a year ago
• Due:
• Budget: \$4