a brass rod of length 0.40 cm and steel rod of length 0.60cm, both are initially at 0 degree celsius are heated to 75 degree celsius. if the increase in length is the same for both the rods, calculate the linear expansivity of brass. given alpha for steel is 12*10 power -6​

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?