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Physics 236 Sample Test #1

k = 9.00 x 10⁹ Nm²/C²; e₀ = 8.85 x 10^-12 C²/Nm²; e = 1.60 x 10^-19C;

m_e = 9.11 x 10^-31 kg; m_p = 1.67 x 10^-27 kg

1) Calculate the electric field required to accelerate a proton from 2.87 x 10⁵ m/s to

5.32 x 10⁵ m/s in a distance of 3.15 cm.

Ans: 33200 N/C

2)

In the figure Q1 = +2.4 mC and Q2 = -3.1 mC. A berylium ion of mass 1.5 x 10^-26 kg and charge +1.0 e is released from rest at point A. Find its speed when it reaches point B.

Ans: 2.07 x 10⁷ m/s

3)

In the figure Q1 = +1.5 mC, and Q2 = - 2.5 mC.

a) Calculate the magnitude and direction of the resultant electric field at point P.

b) Calculate the potential at point P.

Ans: a) 5.1 x 10⁶ N/C ’ 108⁰

b) 1.7 x 10⁴ v

4) V = 12v, C1 = 3.0 mF, C3 = 4.0 mF

The charge on C1 is 24 mC.

a) Calculate the value of C2.

Ans: 6.0 mF

b) Calculate the total energy stored in the circuit.

Ans: 430 J