Q1. (a) A solid block of timber strut of density 850 kg/m and volume 0.6 m floats in a liquid of density 1250 kg/m. i. What is the mass of the block?. (3 marks) ii. What is the weight of liquid displaced by the block? (3 marks) iii. Find the volume of the timber strut that is submerged below the surface of the liquid. (3 marks) iv. Find the minimum force required to keep the block totally submerged in the liquid. (3 marks) (b) The fabric and basket of a balloon for aerial survey weigh 5000 N and are of negligible volume. The balloon is inflated with 1250 m of helium and moored in still air by a cable as shown in below figure. basket cable i. What is the upthrust acting on the balloon? ii. Find the weight of helium inside the balloon. iii. Find the tension in the cable. iv. (3 marks) (3 marks) (3 marks) If the cable is cut, find the acceleration of the balloon with which it rises. (4 marks) (Densities of air and helium are 1.3 and 0.18 kg/m respectively)