A piece of wire length 30cm and cross sectional area of 0.5mm^2 has a resistance of 5ohms at 20°c. It is then heated to a temperature of 150°c. Calculate it's resistivity at 20°c

What determines the amount of inertia an object has

What is the measurement of how fast an object moves relative to a reference point?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?