Grade 10 Physics Regular Assessment 2 Review PDF

1/15/2024 Equations of Energy: What are the GPE = 𝑚𝑔ℎ units for each? KE = 𝑚𝑣 Work = Force (parallel) x distance Efficiency = ⋅ 100%...

1/15/2024 Equations of Energy: What are the GPE = 𝑚𝑔ℎ units for each? KE = 𝑚𝑣 Work = Force (parallel) x distance Efficiency = ⋅ 100% Power = Energy / Time 1 Conversions of Units (Easy) 12 km = ? m 3.5 MJ = ? J 460 mm = ? m 3.25 h = ? s Practice this until it is second nature! 2 Conversions of Units (Hard) 210 km/h = ? m/s 330 m/s = ? km/h 3 1  1/15/2024 Name the type of energy that is considered the “energy of motion”. Kinetic Energy 4 What are some examples of “potential” energy? Gravitational Potential Energy Chemical energy (battery) Elastic energy (stretched spring or elastic) 5 Alan drops a steel ball bearing from 1 m above his desk. If the mass of the ball bearing is 500 g, how much GPE does it have, relative to the desk, before he drops it? 6 2  1/15/2024 The ball bearing falls and impacts with the surface of the desk. Assuming no energy losses through friction, heat, etc., how fast was it going immediately before impact? 7 8 9 3  1/15/2024 The aircraft accelerates from rest along the deck. At take-off the aircraft has a speed of 75 m/s. The mass of the aircraft is 9500 kg. Calculate the kinetic energy at take-off. 10 The aircraft accelerates from rest along the deck. At takeoff the aircraft has a speed of 75 m/s. The mass of the aircraft is 9500 kg. Calculate the kinetic energy at takeoff. 1 𝐾𝐸 = 𝑚𝑣 𝑣 = 75 m/s 2 1 𝑚 = 9500 kg 𝐾𝐸 = (9500 kg)(75 m/s) 2 𝐾𝐸 = 26,718,750 J 𝐾𝐸 = 27 MJ 11 12 4  1/15/2024 Find the efficiency of the light from the earlier example where 100 J was put in, and 40 J was converted to useful light energy. 13 The dog pull the man 20 meters. How much work is being done by the dog? What about gravity? 200 N 14 200 N 15 5  1/15/2024 200 N 16 A large elevator is used to move 20 passengers every minute from the first floor of a department store to the second. The second floor is located 5-meters above the first floor. The average passenger’s mass is 60 kg. Determine the power requirement of the escalator in order to move this number of passengers in this amount of time. 17 18 6  1/15/2024 Thermal conduction is the transfer of thermal (heat) energy through the vibration of atoms within the substance. The substance itself does not move. 19 Convection is the transfer of heat through fluids (liquids and gases) by the upward movement of warmer, less dense regions of fluid. 20 21 7  1/15/2024 Radiation is the transfer of energy through infra-red waves. Remember, infra-red waves are part of the electromagnetic spectrum 22 Why do some things “feel” hotter or colder even though they are the same temperature. Why does the metal table feel colder than the wooden table in the same room? 23 Metals tend to conduct heat Non-metals such as Wood or better as their free electrons plastics tend to be insulators as can transfer the heat faster they do not have free electrons through out the material. to help transfer the energy. Asbestos: A very good insulator but also deadly 24 8  1/15/2024 The aim of insulation is to minimize the rate of heat transfer by conduction, convection and radiation. Gasses Stop movement Reflection Vacuum of fluid 25 9