Which of these choices states Newton’s law of universal gravitation? 1) As a planet moves around its orbit, the planet sweeps out equal areas in equal amounts of time.
2) The orbit of a planet, or other body, around the sun is an ellipse with the sun at one focus of the ellipse.
3) The square of a planet’s orbital period is proportional to the cube of the planets mean distance from the sun.
4) Gravitational force increases as the mass of an object increases or as the distance between two objects decreases.

What reaction is taking place? 02 + c3h8 = h20 + co2

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size