Science 3

2. a) Interpret the types of stresses based in Figure Q2(a). (m) TENSION OUTSIDE OF BEND BENT STRUCTURAL MEMBER SHEAR ALONG IMAGINARY LINE (DOTTED) COMPRESSION INSIDE OF BEND (iv) (v) Figure Q2(a) [5 marks] b) A barber raises his customer's chair by applying a force of 150N to a hydraulic piston of area 0.01 m as shown in Figure Q2(b). Compute the maximum mass of a customer can be lifted if the chair is attached to a piston of area 0. 1 my. Assume the chair itself has a mass of 5 kg. Figure Q2(b) [4 marks] c) Predict with reasons the name of device A and device B as shown in Table Q2(c) which is used to measure pressure. Table Q2(c) Differences B Close-ended with Vacuum Yes Yes Open-ended tube No Yes Modern digital sensors Yes Yes Mercury Inside Yes Yes Light Liquids Inside No (Unusual) Yes Calculate Atmospheric Yes Pressure Yes Calculate Other Pressures No Yes [4 marks] d) Sharifah plans to make some silver charms for a bracelet. It is assumed that the melting point of silver is 960.8 "C, the specific heat of silver is 0.235 kJ/(kg. "C), and the latent heat of fusion of silver is 88.3 kJ/kg. Compute the heat that must be added to 0. 700 kg of silver at 100.0 "C to be able to pour silver into the moulds. [6 marks] e) A 2.0 KW heater is used to heat a room from 5'C to 20C. The mass of air in the room is 30 kg. Under these conditions, the specific heat capacity of air = 1000 Jkg"K-. Calculate the minimum time required to heat the room. [5 marks]