Assignment 1. (a) Define the following.
(i) electromotive force (ii) internal resistance of a cell (iii) lost volt (iv) electrical charge (v) potential difference (vi) electrical resistance
(b) State Ohm's law.
(c) State what the following units measure. (i) volt (ii) ampere (iii) ohm
(d) What instrument is used to measure each of the following? (i) current (ii) voltage (iii) electromotive force
2. (a) Derive an expression for the resistance of three conductors connected in (i) series (ii)parallel
(b) A cell has an e. m.f of 2.0 V and internal resistance of 1.5 ohm and is connected to two resistance 3 and 4 ohms in series. Find the current flowing and potential difference across the ends of each resistor.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?

The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2