TO BE WRITTEN IN THE CLASS WORK BOOK LAST DATE OF SUBMISSION- 3/9/21, 5:00 P.M L12- PRESSURE Answer the following:- 1. A suitcase of mass 25 kg measures 10 cm x 40 cm x 1.2 m. i) Calculate the weight of the suitcase. ii) Draw a diagram to show how the suitcase must rest to exert maximum pressure on the ground. iii) Calculate the maximum pressure (in Pa) that the suitcase can exert. iv) Calculate the minimum pressure (in Pa) that the suitcase will exert on the ground. 2. Why does a fountain pen ink leak at a high altitude? 3. Sumit wanted to study the variations in the atmospheric pressure on a hot summer day. He took the readings at 6am in the morning and recorded it. Later at 12 O’clock, he took the second reading, followed by the third reading at 6 pm. How does the atmospheric pressure change? Does it increase, decrease or remain the same? Give a reason for your answer. 4. Why are water tanks placed at a certain height? 5. If the area of our head is 15cm x 15 cm, the weight of air on our head will be 225 N. Why doesn’t such a large weight of the air crush us? 6. Observe the given diagram and answer the following questions giving suitable reasons: i) In which of the cases A,B or C is maximum pressure exerted? ii) In which of the cases A,B or C is the pressure exerted the same? 7. An inflated balloon is placed in a jar, which is connected to a vacuum pump. What happens if the air inside the jar is pumped out? 8. How can pressure be increased by exerting the same force? 9. Calculate the mass of an object exerting 2000 Pa of pressure on an area of 200 cm2 . ____________________________________________________