Andre is studying snails and how fast they travel. he observes three groups of snails containing four snails each. here are the recorded observations from andre’s notebook: group a snails averaged a speed of 4.7cm/min in a petri dish. group b snails averaged a speed of 2.8 cm/min on sandpaper. group c snails averaged a speed of 3.3 cm/min in the dirt. based on this data, what is affecting the snails’ speed?

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

1400 kg car has a speed of 27 m/s. if it takes 7 s to stop the car, what is the impulse and the average force acting on the car?

Phase changes are chemical changes. true or false