Why is it that the properties of pure substance do not vary from sample to sample

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.

Atorque acting on an object tends to produce a. equilibrium b. rotation c. linear motion d. velocity e. a center of gravity

Gravity is pulling an object into the sun. the closer the object gets to the sun, the greater the gravitational force that acts on the object, increasing its acceleration. a line graph plotting the speed of the object against time would have which shape? a: straight line of positive slope b: curved line that slopes upward c: curved line that slopes downward d: straight line of negative slope