The energy of a moving object is called kinetic energy * True False Negative work means the force applied is opposite to the direction of motion True False Efficiency is the ratio of the energy required to operate a device to the useful energy provided by the device True FalseA boy decides to ignite caps from a top gun in the following manner. He uses a magnifying glass to focus the sun's rays on a cap. It ignites with a loud bang. Which of the following energy transformations best describes the situation? a) sound - chemical - radiant d) sound - radiant - chemical b) radiant - chemical - sound e) none of the above c) chemical - radiant * sound a) ( B) O C) O D) O E)The unit of work is the Joule (J) which is equivalent to: * a) kg.m/s d) watt b) kg-m/s e) kgm /s2 c) kg-m's O O B O C O D O E The work done on a system is equal to its change in: * O energy O height O power O speedA student uses a force 5N to push a box 4 m across the floor. The work done by the student on the box is O o J 20 J O 40 J 60 J A construction worker does 450 J of work in lifting a load of bricks from the ground to a support stand 1.50 m from the ground. What was the mass of the bricks she lifted? O 300 kg 3.06 kg O 68.9 kg 30.6 kgA ball is dropped from some height. During the drop, the balls potential energy: increases O decreases O remains the same A ball is dropped from some height. During the drop, the balls kinetic energy: O increases O decreases O remains the sameMachine A does 100 J of work in 10 s. Machine B does 100 J of work in 5 s. Which machine has the greatest power output? Machine A Machine B The power output is the same It cannot be determined When a student pushes on a wall with a force of magnitude 250 N, the work done on the wall is zero. True O FalseThe specific heat capacity of iron is 450 J/(kg.C). What quantity of heat is required raise the temperature of 5.0 kg of iron from 10*C to 40*C? O 90000 J O 675000 J 3.0 J O 225000 J 75 J The amount of thermal energy needed to change 1 kg of ethyl alcohol from a liquid to a gas it its O specific heat capacity O specific latent heat of fusion O specific latent heat of vaporization O kinetic energyWhat is the basis of thermal energy? * O the random motion of atoms and molecules O the accumulation of static charges on a surface the stretching and twisting of molecules O the interaction of protons and neutrons in atoms What is the equivalent of 93.5 degrees C in kelvins? * O 61.5 K O 2179.5 K O 366.5 K O 179.5 KThe graph shown below represents the uniform cooling of a substance, starting as a gas above it's boiling point. Which segment of the curve represents a time when both the liquid and solid phases are present? 150 C 100 Temperature ('C) HHHHHHHHHH E 60 0 1 2 3 4 5 6 7 8 9 10 11 12 18 14 Time (minutes) O AB O BC O CD O DE O EFA solid substance is heated at a constant rate. The graph below shows the changes in temperature of this substance. What is the melting point of the substance and the total time required to completely melt the substance after it has reached its melting point. Temperature Versus Time for a Sample 200 ] 180 160 140 120 Temperature (C) 0 2 3 5 6 7 8 9 10 11 12 13 14 15 16 Time (min) 50 degrees Celsius in 3 mins 50 degrees Celsius in 5 mins O 100 degrees Celsius in 4 mins 100 degrees Celsius in 14 minsWhat occurs when a substance melts? * O It changes from solid to liquid and heat is released It changes from solid to liquid and heat is absorbed It changes from liquid to solid and heat is released It changes from liquid to solid and heat is absorbed Which term describes a nuclear reaction in which the nuclei of two atoms fuse together to form a larger nucleus? O Beta decay Alpha decay O Gamma decay Nuclear fusionThe half-life of radon-222 is 3.82 days. How much of a 100.0 g sample of radon will be left after one week? 28.1 g 83.4 g O 50.0 g 32.2g When a uranium 238 atom undergoes alpha decay, what is the atomic number of the new isotope? O 92 O 90 O 234 O 242The helium-4 nucleus is called a beta particle. * O True O False During beta positive decay, the nucleus of the atom emits and electron. O True O False