Arunner taking part in the 200 m dash must run around the end of a track that has a circular arc with a radius of curvature of 45 m. the runner starts the race at a constant speed. if she completes the 200 m dash in 21.6 s and runs at constant speed throughout the race, what is the magnitude of her centripetal acceleration (in m/s2) as she runs the curved portion of the track?

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air

Why does lightning travel from clouds to the ground?

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.