What is the velocity of this object from t = 6s to t = 9s

Density of salty water as compared to the density of pure water is(a) is less(b) is always equal(c) is always more(d) may be less or more

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.