A small 12.0 g plastic ball is tied to a very light 26.8 cm string that is attached to the vertical wall of a room. (See (Figure 1) .) A uniform horizontal electric field exists in this room. When the ball has been given an excess charge of ?1.20?C, you observe that it remains suspended, with the string making an angle of 17.4? with the wall.

 

Part A

Find the magnitude of the electric field in the room.

Express your answer in newtons per coulomb to three significant figures.

17.4