Plzz best answer will get marked (sorry cant spell)radioisotopes often emit alpha particles, beta particles, or gamma rays. the distance they travel through matter increases in order from alpha to gamma. each radioisotope has a characteristic half-life, which is the time needed for half of a sample of radioisotope to undergo nuclear decay. the table lists isotopes of the element calcium. based on the table, which isotope is best suited for use as a radioactive tracer for the body’s use of calcium? calcium-40calcium-45calcium-47calci um-49

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

Find the dimensions and area of the largest rectangle that can be inscribed in the upper half of the ellipse. (give your answers in terms of a and b. enter the dimensions as a comma-separated list.)

Acarpenter builds an exterior house wall with a layer of wood 2.9 cm thick on the outside and a layer of styrofoam insulation 2.3 cm thick on the inside wall surface. the wood has k=0.080w/(m⋅k), and the styrofoam has k= 0.010 w/(m⋅k). the interior surface temperature is 19.0 ∘c , and the exterior surface temperature is -15.0 ∘c . a.)what is the temperature at the plane where the wood meets the styrofoam? celsius b.)what is the rate of heat flow per square meter through this wall? /m^2