A father pushes his child in a cart. The cart starts to move. Scientists can use many physical quantities to describe what is happening.

The car is placed on a ramp, which is 20 meters high. The mass of the car and the child is 100kg.

Calculate the potential energy the car will have before it is let go and the velocity the car will travel at down the ramp assuming no frictional forces.

Acceleration due to gravity (g) = 10 m/s2

An observer that stands still as the electron moves by him, will observe

Name two kinds of practical electric pumps.

An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states