An alpha particle (α), which is the same as a helium-4 nucleus, is momentarily at rest in a region of space occupied by an electric field. the particle then begins to move. find the speed of the alpha particle after it has moved through a potential difference of −3.45×10−3 v .

the charge and the mass of an alpha particle are qα = 3.20×10−19 c and mα = 6.68×10−27 kg , respectively.

if you had carried out the algebra using variables before plugging numbers into your expressions, you would have found that

(vf)α=−2qαδvmα√,

where δv is measured in volts. to verify that this expression for (vf)α has the correct units of velocity, you need to perform some unit analysis. begin by finding the equivalent of a volt in terms of basic si units. what is a volt in terms of meters (m), seconds (s), kilograms (kg), and coulombs (c)?

answer includes c

Aheat engine running backward is called a refrigerator if its purpose is to extract heat from a cold reservoir. the same engine running backward is called a heat pump if its purpose is to exhaust warm air into the hot reservoir. heat pumps are widely used for home heating. you can think of a heat pump as a refrigerator that is cooling the already cold outdoors and, with its exhaust heat qh, warming the indoors. perhaps this seems a little silly, but consider the following. electricity can be directly used to heat a home by passing an electric current through a heating coil. this is a direct, 100% conversion of work to heat. that is, 19.0 \rm kw of electric power (generated by doing work at the rate 19.0 kj/s at the power plant) produces heat energy inside the home at a rate of 19.0 kj/s. suppose that the neighbor's home has a heat pump with a coefficient of performance of 4.00, a realistic value. note: with a refrigerator, "what you get" is heat removed. but with a heat pump, "what you get" is heat delivered. so the coefficient of performance of a heat pump is k=qh/win. an average price for electricity is about 40 mj per dollar. a furnace or heat pump will run typically 200 hours per month during the winter. what does one month's heating cost in the home with a 16.0 kw electric heater? what does one month's heating cost in the home of a neighbor who uses a heat pump to provide the same amount of heating?

Ateacher gives students four liquids commonly found in the kitchen - vinegar, apple juice, dish detergent, and milk - and ph indicator strips, which measure acidity. the teacher asks the students to put the liquids in order from most acidic to most basic. what type of investigation could the students conduct to determine the correct order for the liquids?

Discuss the difference between thermal energy and heat. (terrance) terrance, egolf, r., congdon, donald. physical science student text, 5th edition. bju press, 2014. vitalbook file.