A frictionless cart attached to a spring vibrates with amplitude A. Determine what fraction of the total energy (Etot) of the cart-spring system is elastic potential energy (Us) and what fraction is kinetic energy (K) when the cart is at position x=A/2.

More solar radiation is absorbed by earth’s surface than by

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?