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The following statements are about motion. 1 A plane flies due East for 600 km. 2 A runner’s average speed in a race around a track is 5 m / s. 3 A snail crawls at 3 mm / s in a straight line towards a lettuce. 4 A tourist travels 500 km on a journey. Whi 1 and 2, 1 and 3, 2 and 3 , 2 and 4
Power is measured in watts.What is the correct symbol for millions of watts? mw, mW , Mw, MW
A student measures the speed of a trolley. At one instant, the speed of the trolley is 1.0 m / s and two seconds later the speed is 4.0 m / s. What is the acceleration of the trolley? 1.5 m / s2 , 2.0 m / s2, 2.5 m / s2 , 5.0 m / s2
A passenger is sitting in an aeroplane, which takes off and climbs to 10 000 m. During this time, what happens to the mass and to the weight of the passenger? decreases decreases, increases increases, unchanged decreases, unchanged increases
A small emergency generator supplies 432 000 000 J of electrical energy in twenty-four hours. What is the average power output of the generator? 5000 W, 300 000 W, 18 000 000 W, 432 000 000 W
A parachutist has opened his parachute and is falling to Earth at constant speed. What is the principal energy conversion taking place as he falls? kinetic energy ? potential energy, kinetic energy ? thermal energy (heat), potential energy ? kine
An ice-cube has of mass of 7.50 g. The ice-cube is at 0 °C. Heat from the surroundings reaches the ice-cube at an average rate of 1.25 J / s.How long does it take for all of the ice to melt?(specific latent heat of fusion of ice = 333 J / g) 35.5 s, 55.5 s , 2000 s, 3120 s
The liquid in a puddle evaporates and this causes its temperature to change. How does the temperature of the liquid change and why? decreases less energetic molecules leave the liquid, decreases more energetic molecules leave the l
Convex lenses are used in cameras and as magnifying glasses. Which types of image are formed? type of image in camera real type of image in magnifying glass real, type of image in came
A flash of lightning and the corresponding sound of the thunder are detected 6 s apart. A student calculates that the lightning struck about 1800 m away On which assumption is the calculation based? Light reaches us almost instantaneously, but sound travels at 300 m / s., Light travels 300 m / s f
A hospital needs to sterilise medical equipment. Which electromagnetic waves could be used? infra-red, microwaves, radiowaves, ultraviolet
Which properties make materials suitable for use as a core in an electromagnet? difficult to magnetise and easy to demagnetise, difficult to magnetise and retains magnetic strengt
Which quantity is measured in kilowatt-hours? charge, current, energy, power
The metal case of an electric heater is earthed. The plug to the heater contains a 5 A fuse. There is a current of 4 A when the heater works normally. The cable to the heater becomes so worn that the live wire makes electrical contact with the case. What happens? The current flows to earth and the fuse is not affected., The fuse melts and switches off the circu
Which row is correct for fission and for fusion? produces larger nuclei is the energy source of a star, produces larger nuclei is used to release en
Proton number is another name for atomic number. Nucleon number is another name for mass number. What are isotopes? nuclei with different proton numbers and different nucleon numbers, nuclei with different proton num
When a sample of a radioactive nuclide decays, the count rate falls from 1200 to 150 in three minutes. What is the half-life of the radioactive nuclide? 0.75 minutes, 1.0 minutes, 3.0 minutes, 9.0 minutes