Technician A says That drum brakes expand. Linings against a rotor to slow the vehicle. Technician b say that power brake booster reduces. the amount of force applied to the master cylinder . who is correct?

Cold water (cp=4180j/kg k) leadıng to a shower enters a thin-walled double-pipe heat transfer at 15c at a rate of 0.25kg/s and is heated to 45c by hot water (cp=4190j/kg k) that enters at 100c at the rate of 3kg/s. if the overall heat transfer coefficient is 950w /m2 k , determıne the rate of heat transfer and the heat transfer surface area of the heat exchanger using e - ntu method