Which of the following phrases best describes a physical model?

A. An exact copy of an object, system, or process
B. A chemical formula
C. A graph or equation
D. A representation of an object, system, or process

An object starts from rest at point f and speeds up continuously as it moves around an oval. a. choose a point about 1/8 th of the way around the oval from point f, and label it point g. draw a vector to represent the velocity of the object at point g. b. determine the change in velocity vector   between points f and g.

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)