Question

PHYSICS 1112 Chapter 21-WarmUp due 23 January. Reading Objectives Name: . There are many types of potential energy including the usual gravitational (think mgy) and elastic (think KX"72), You wall be introduced to electric potential energy (in Joules) and how it's related to electric tential (in Volts) on the bottom of page 667. This section can be tough sledding so be patient. We'll up the mess and get in some comfort zone in class. We'll be particularly interested in distinguishing electric potential energy" and "electric potential". Stay tuned. We'll spend a good bit of time applying equation 21.2 which is an electric version of stuff you did in PFHYS 1111. Note that potential enengy is computed using qv The device shown in Figure 21.5 should look familiar from our very first lab session. I called it a DMM Warm-up 1. PHYS 1111 Review: A greased pig slides without friction down an inclined plane. What is its kinetic energy at the very bottom of the ramp? Include units on your answer CO KE t003 2. How much clectric potcntial encrgy does a 20 C charge have if it is located at a position where the electric potential is 30.0 V? Refer to section 21.1 in your text. Make sure you include units on your final answer.

Answer 1

Principle of conservation of energy Total mechanical energy at top of incline = KE + u = 100 + 400 = 500 J Total mechanical at bottom energy = total mechanical energy at top At bottom of incline potential energy will be zero (as h = 0] therefore kinetic energy at bottom = total mechanical energy at top therefore kinetic energy at bottom = 500 J U = q V q = 2.0 C & V = 30.0 V therefore Electric potential energy U = q V = 2.0 times 30.0 = 60.0 J