What is the formula of moment of force

Aspecial electronic sensor is embedded in the seat of a car that takes riders around a circular loop-the-loop ride at an amusement park. the sensor measures the magnitude of the normal force that the seat exerts on a rider. the loop-the-loop ride is in the vertical plane and its radius is 23 m. sitting on the seat before the ride starts, a rider is level and stationary, and the electronic sensor reads 740 n. at the top of the loop, the rider is upside down and moving, and the sensor reads 370 n. what is the speed of the rider at the top of the loop?

Two polarizers are oriented at 70∘∘ to one another. unpolarized light falls on them. what fraction of the light intensity is transmitted?

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