Two people use a ramp to move a heavy box onto a truck. The box weighs 750 N. The mechanical advantage of using the ramp is 4. How much effort is required to move the box?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

Why do oxygen have a strong attractive force for electrons