A small boat is crossing a lake on a windy day. During some interval of time, the boat undergoes the given displacement Δ → r . Δr→. Δ → r = ( 3.11 m ) ^ ı + ( 2.69 m ) ^ ȷ Δr→=(3.11 m)ı^+(2.69 m)ȷ^ During the same interval of time, the wind exerts the given constant force → F F→ on the boat. → F = ( 263 N ) ^ ı − ( 131 N ) ^ ȷ F→=(263 N)ı^−(131 N)ȷ^ What is the total work done on the boat by the wind over this period of time?

You are a sales representative for a company that makes a new alternate fuel for vehicles. you have prepared a presentation for the environmental engineers to sell your new product. what question do you expect the audience to ask regarding whether the new fuel will cause less damage to the environment? a. do we have to change any parts of the vehicle to use this alternate fuel? b. will the vehicles get better fuel mileage with the alternate fuel? c. how much greenhouse gas does your fuel produce compared with current fuel sources? d. is the alternate fuel more expensive than fossil fuel?

In science and physics what is the standard unit of measure for speed?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.