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Miracle Learning Centre Science Tuition Question on Pressure (O Level Science Tuition/IP Science Tuition/Secondary Science Tuition)

1. The hydraulic system shown in the diagram below contains an incompressible liquid. A downward force of 3 N is exerted on the smaller piston.

Calculate (a) the pressure, in Pa, exerted by the 3 N force (b) the magnitude of the force X that is necessary to balance the system. 2) Amy is worried about burglars. She puts a pressure sensor on the floor near her front door. She is going to connect the sensor to an alarm circuit. The alarm will make a noise when someone treads on the sensor. Amy studies the data sheet that comes with the sensor. She finds the graph shown below.

(a) Write down the equation for calculating pressure. ………………………………………………………………………………….. (b)Amy has a weight of 600 N. If the sensor has an area of 30 cm2, calculate the pressure on the sensor in N/cm2, when she stands on the whole sensor barefoot. pressure = …………………….. (c)Use the graph to find the resistance of the sensor when Amy stands on it. resistance = …………………….. (d) Suppose the alarm will only ring when someone treads on the whole sensor barefoot with a minimum pressure of 18 N/cm2. Explain why her pressure sensor may not be practical. …………………………………………………………………………………….. ………………………………………………………………………………….. Miracle Learning Centre Answer to Science Tuition Question on Pressure (O Level Science Tuition/IP Science Tuition/Secondary Science Tuition) 1a) p = F/A = 3 / 0.0002 = 15 000 Pa b) Force X = p A = 15 000 x 0.0006 = 9 N 2) Amy is worried about burglars. She puts a pressure sensor on the floor near her front door. She is going to connect the sensor to an alarm circuit. The alarm will make a noise when someone treads on the sensor. Amy studies the data sheet that comes with the sensor. She finds the graph shown below.

(a) Write down the equation for calculating pressure. P = F / A (b) Amy has a weight of 600 N. if the sensor has an area of 30 cm2, calculate the pressure on the sensor in N/cm2, when she stands on the sensor. pressure = …………………….. (c) Use the graph to find the resistance of the sensor when Amy stands on it. resistance = …………………….. (d)Suppose the alarm will only ring when someone treads on the sensor with a minimum pressure of 18 N/cm2. Explain why her pressure sensor may not be practical. For the alarm to work, the person stepping on the sensor must be at least 540 N. If the person is lighter, the sensor would not work. Learn from our Science Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Science tuition, Maths tuition, Chemistry tuition and Physics tuition classes.