The resistance r of a piece of wire has thermometric properties which can be described as a linear function of temperature (t), see below: where a and b are constants. the resistance of the wire is found to be 3.3 2 at the temperature of melting ice (0 °c) and 8.5 2 at the boiling of water (100 °c) at atmospheric pressure. [15 marks] a, find a and b b. determine the temperature when r is 6.9 2

Carbon-14 is a radioactive element that undergoes beta decay. which force is responsible for allowing carbon-14 to become stable? electromagnetic gravitational weak nuclear strong nuclear

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?

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.