How much water to add to 80 lb bag of concrete?

A space vehicle is traveling at 2980 km/h relative to Earth when the exhausted rocket motor is disengaged and sent backward. The relative speed between the motor and the command module is then 94 km/h.

Why are the phases of the Moon so predictable that they can be published on calendars that are printed at least a year ahead of time?

Why was Copernicus's heliocentric model not believed until gailileo and Kepler provided more evidence?

Could an average star, such as our sun, become a neutron star?

In World War II, there were several reported cases of airmen who jumped from their flaming airplanes with no parachute to escape certain death. Some fell about 20,000 feet (6000 m), and some of them survived, with few life-threatening injuries.

The force of repulsion between two like-charged particles will increase if

An automobile tire having a temperature of -2.6°C (a cold tire on a cold day) is filled to a gauge pressure of 24 lb/in^2 What would be the gauge pressure in the tire when its temperature rises to 43◦C?

Compared to that of a plane on the ground, Earth's gravitational pull on a plane 7 miles above Earth is approximately A) zero. B) the same. C) half as much. D) twice as much.

With what velocity does it hit the ground?

What chemical phenomenon accounts for the elasticity seen in solids? covalent bonds, hydrogen bonds, ionic bonds, all of the above