ID: A Which is an example of heating through convection? a warm air rising towar
ID: 1585366 • Letter: I
Question
ID: A Which is an example of heating through convection? a warm air rising toward the ceiling b. touching a hot stove c using a greenhouse to grow plasts in winter 7. d. The sun heats up the inside of a car 8, which is the transfer of thermal energy through direct contact of particles? a. conduction b. radiation d. specific heat 9. The cross-sectional area of an air pimn is 8.70×10-s m, when the piston is pushed in a downward directioe, the internal pressure is 19.0 kPa more than the atmospheric pressure. Calculate the force with which the piston should be pushed if the atmospherie pressure is 1013 kPa e. 10.5N d. 218x 10N a. 7.16 N b. 1.65 N 10. How much pressure is exerted by a free of600 N spread over a 20 ma area? a 30 N _ e. 30 Pa d. 12000 Pa b. 2700 Pa 11. Which is not a unit of pressure? b. Pa A gas is collected in a 424 L container at 0°C. The pressure of the gas is determined to be 137 kPa. a. Nm c. kPa d. N/cm 12. Determine the number of moles of gas present. 0.256 moles b. 0.0209 moles c. 0.0025 moles d. 5.724 moles 13. A sample of gas has a volume of 0.35 m2 and a pressure of 1.42 kPa when it is at 273 K. What will the new pressure be if it is allowed to occupy a volume of O.63 m2 at a temperature of 340 K? a. 0.63 kPa b. 29000 kPa e. 3.2 kPa d. 0.98 kPa 14. A rectangular block with dimensions 4 cm x 4 x 10 crn has a weight of 750 N. By what factor is the pressure it exerts increased when it is standing on its smaller end compared to when it is lying on its side? a. 4 times b. 2.5 times c. 18.75 times d. 4.7 times A hydraulic piston is used to lift 1030 N using 45 N of force. If the platform supporting the weight has an area of 1.2 m2, what is the area of the piston that force is applied to? a 0.036 b. 15. c. 19.1 m d. 0.052 m2 275m? Problem 16. The temperature of a 2-kg metal block rises by 10°C when 8000 J is supplied to it. What is the specific heat of the metal?Explanation / Answer
There are a large number of problems.
I am going to solve first four of your questions.
(7) Option (d) is the correct answer.
Explanation -
Inside the car temperature rises due to conduction. Rest option are not conductions.
(8) Option (a) conduction, is the correct answer.
Explanation -
Direct contact of particles means conduction.
(9) The pressure through which the piston moves P = 19.0 + 101.3 = 120.3 kPa = 120.3 x 10^3 Pa
Area A = 8.70 x 10^-5 m^2
So, the requisite force F = P*A = 120.3 x 10^3 x 8.70 x 10^-5 = 10.46 N = 10.5 N
Therefore, option (c) is the correct answer.
(10) Pressure P = Force / area = 600 / 20 = 30 N/m^2 = 30 Pa
Therefore, option (c) is the correct answer.