2019年11月IB物理(SL)真题PDF下载-Paper2
1. The graph shows the variation with time t of the horizontal force F exerted on a tennis ball by a racket.
The tennis ball was stationary at the instant when it was hit. The mass of the tennis ball is 5.8*10–2 kg. The area under the curve is 0.84 N s.
(a) Calculate the speed of the ball as it leaves the racket.
(b) Show that the average force exerted on the ball by the racket is about 50 N.
(c)Determine, with reference to the work done by the average force, the horizontal distance travelled by the ball while it was in contact with the racket.
(d)Draw a graph to show the variation with t of the horizontal speed v of the ball while it was in contact with the racket. Numbers are not required on the axes.
2.The air in a kitchen has pressure 1.0 × 105 Pa and temperature 22°C. A refrigerator of internal volume 0.36 m3 is installed in the kitchen.
(a)With the door open the air in the refrigerator is initially at the same temperature and pressure as the air in the kitchen. Calculate the number of molecules of air in the refrigerator.
(b) The refrigerator door is closed. The air in the refrigerator is cooled to 5.0°C and the number of air molecules in the refrigerator stays the same.
(i) Determine the pressure of the air inside the refrigerator.
(ii) The door of the refrigerator has an area of 0.72 m2. Show that the minimum force needed to open the refrigerator door is about 4 kN.
(iii) Comment on the magnitude of the force in (b)(ii).
2019年11月IB物理(SL)真题余下省略！
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