Worksheet #3 - Electric Potential Energy Date: 1. Find the Ep for each of the following 8. A proton is released 2.0 x 10'll m from the centre of a 6.4 x 10-18 C fixed charge. What is the 10 x 10' m speed of the proton when it is 0.50 m from the charge? 0.50 m O O electron proton +1.0 AC +3.0 HC 9. How much work is required to move a 350 kg satellite that is in orbit (it's moving!) 550 km above Earth to an orbit that is 1200 km above Earth? 10. How much work is done against the electric field produced by a 5.0 JC charged object when a 2. Find the work done by an external force that moves a +3.0 uC from infinity and places it 50 cm 0.030 HC charge is moved from a distance of 45 cm to 15 cm? from a fixed +2.0 AC charge. initial O +3.0 HC 1 1. What is the escape velocity of an object that is on the surface of Mars? MMars = 6.4 x 1023 kg, radius = 3400 km +2.0 HC final +3 .0 HC Both charges begin and O O end at rest 12. A moon orbits a massive Neutron star at a distance of 7.5 x 105 m. Its orbital speed is 10.0% of the speed of light. Find the mass of the star. 3. A massive asteroid approaches Earth from a great distance at a speed of 3000 m/'s. Find its 13. What is the maximum mass of moon of radius 2.5 x 10* m required in order for there to be velocity at impact. an escape velocity of 4000 m/s? 4. A 1.00 mC. 1.00 g charge is placed 10.0 cm from a fixed 2.00 mC charge and allowed to 573.1 X 10 J move. Find the speed of the charge when it has moved 20.0 cm. 1) -2.3 x 10'17 J, 0.054J 2) 0.11 J 3) 1.16x10* m/s 4) 1.55 x 10' m/s 43.0 x 1032 J 6) 0.7291 7a) 1.80x 103 N 7b) 112 N 7c) 6.75 kJ 8) 7.4 x 105 m/s 9) 6.9 x 1030 ] Fixed +2.00 mC Moves +1.00 mC 10) 6.0 x 10*J 11) 5.0x103 m/s 12) 104 kg or "no star has such a large mass!!" 13) 3.0 x 10" kg O 0.100 m OK 0.200 m 5. Calculate the Ep of a 3.4 x 1020kg moon that is 4.2 x 105 m from a planet with a mass of 5.8 x 1025 kg. 6. Find the work done in moving a +2.00 pC charge from a point 5.00 m away to a point 2.00m away from a fixed 135 uC charge. 7. A-5.00 mC charge is 5.00 m from a +1.00 mC charge. The -5.00 mC is moved another 15.0 m away from the +1.00 mC (total distance 20.0 m). a) Find the initial force between the charges b) Find the final force between the charges c) Calculate the work done by/on the charges BY NG FA