Three people are trying to move a box. Which set of forces will result in a net force on the box of 20 N to the left?

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?