The marble rolls down a track and around the loop the loop of radius R. The marble has mass m and radius r. What minimum height h must the track have for the marble to make it around the loop the loop without falling off?
A sphere has I of 2/5mr^2
From using Newton's second law, I find the critical velocity to be sqrt(gR).
Using energy conservation, I get the equation
mgh = 1/2mv^2 + 1/2IW + 2Rg

The consumption of fossil fuels could be

What are the similarities & differences between a thermistor and a light dependent resistor in physics?

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.