Cathy Gwynn for a class project is analyzing a "Quick Shop" grocery store. The store emphasizes quick service, a limited assortment of grocery items, and higher prices. Cathy wants to see if the store hours (currently 0600 to 0100) can be changed to make the store more profitable. Time Period Daily Sales in the Time Period 0600-0700 $40 0700-0800 70 0800-0900 120 0900-1200 400 1200-1500 450 1500-1800 500 1800-2000 600 2000-2200 200 2200-2300 50 2300-2400 85 2400-0100 40 The cost ofthe groceries sold averages 65% of sales. The incremental cost to keep the store open, including the clerk's wage and other operating costs, is S23 per hour. To maximize profit, when should the store be opened, and when should it be closed?

Need help with questions D and E. This was all the information I was given. If needed then it would be look up online.

An electric hot water heater consumes 3.1 kilowatts of electricity and converts it to heat. How long will it take the water heater to heat a 67 gallon tank of water from 10 degrees Celsius to 50 degrees Celsius? (1 kilogram of water is 0.37 gallons, 1 Calorie = 4200 J).  It may be helpful to refer back to the weekly handout for guidance on this problem. Your final answer should be in minutes (rounded to the nearest 10 minutes).

Question 11) Roger gave the following account of a roller-coaster ride: 1 tried a brand-new ride at a science centre. There's a computer screen that tells you how much the car and the people in it weigh and how high and fast you travel. You get into the car and they strap you in. The car weighs 600 kg. At the top, it moves horizontally at a speed of 1 m/s. Then you drop 30 m, make a loop into the air and finish by riding over an 8-m hill. I don't remember our maximum speed or our speed at the top of the loop, but the ride was fantastic!" Answer the following questions without taking the force of friction into consideration. Show your calculations for each question. A v=1 m/s 20 m 8 m a) What is the highest speed Roger could have attained? What is the potential energy of the roller-coaster car when it is at the top of the b) loop? c) What is the kinetic energy of the car as it passes over the top of the 8 m hill? d) What is the total mechanical energy of the system?