1.Mention 4 effects of noise. 2.Calculate the absorptivity of a plastic surface that reflects two-thirds of sound energy incident on it. 3.A cylindrical block of concrete is 300mm long and has a circular cross section of 100mm diameter. It experiences a reduction of 0.2% in length under a load of 67kN. i. What is the type and numerical value of of the stress (show working). ii. What is the axial strain (show working). iii. Calculate the modulus of elasticity (show working).​

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?