What is the change in gravitational potential energy for a 70 kg man walking up stairs from a height of 64 m to 108 m? Answer: 30215 J

Question 7 The large piston of a hydraulic lift has a radius of 20 cm. What force must be applied to the small piston of radius 2.0 cm to raise a car of mass 1500 kg to the same level as shown? F₁ Small piston Large piston A₂ F₂

A 1m x 2m inclined plate is submerged as shown. The normal force acting on the upper surface of the plate due to the water (when taking atmospheric pressure into account) is most nearly (A) 68kN (B) 91kN (C) 203kN (D) 294kN Answer is 294kN please write the complete solution in Handwritten format with FBD

A 2-kW baseboard electric resistance heater in a vacant room is turned on and kept on for 15 min. The mass of the air in the room is 75 kg, and the room is tightly sealed so that no air can leak in or out. Solve for the temperature rise of air at the end of 15 min.