Determine the value of a and K when 0.51 is written is scientific nation​

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

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

What properties of a moving object are used in determining the object's energy of motion