Atraffic light consists of a horizontal member attached to a vertical support post. the horizontal member extends 7 m to the left of the support post and has a constant mass density of 15 kg/m. each traffic light has mass of 10 kg, and the street sign has a mass of 5 kg. make sure the connection between the horizontal member and the vertical support post is strong enough to withstand the forces exerted on the horizontal member. calculate the effects of the forces resulting from the two traffic lights and the street sign on the horizontal member.

The energy released by a chemical reaction can be measured using a calorimeter. when barium hydroxide octahydrate crystals are reacted with dry ammonium chloride inside of a coffee cup calorimeter, the temperature of the 18.00 g of water in the calorimeter decreases from 30.0°c to 8.0°c. the equation for calculating energy absorbed or released by a reaction is: where q is the energy released or absorbed, m is the mass of water in the calorimeter, cp is the specific heat of water, and δt is the observed temperature change. if the specific heat of liquid water is 4.19 j/g·°c, how much energy was absorbed by the reaction?