the specific heat of wood is 2.03 j/g. C. how much heat is needed to convert 550 g of wood at -15.0c to 10.0c

Aproton is projected toward a fixed nucleus of charge +ze with velocity vo. initially the two particles are very far apart. when the proton is a distance r from the nucleus its velocity has decreased to 1/2vo. how far from the nucleus will the proton be when its velocity has dropped to 1/4vo?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

The heliocentric and the geocentric models of the solar system included these central principles