Fig. 2.1 shows a sign that extends over a road. The mass of the sign is 8000 kg. The weight of the sign acts at a horizontal distance of 1.8m from the centre of the support post and it produces a turning effect about point P. Point P is a horizontal distance of 1.3m from the centre of the support post

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?

What is the magnitude of the gravitational force acting on the earth due to the sun?