Asteel sphere (sg = 7.8) of 13 mm diameter falls at a constant velocity of 0.6 m/s through an oil (sg = 0.90). calculate the viscosity of the oil assuming that the fall occurs in a large tank and that the reynolds number is very small.

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

How many neutrons does plutonium -196 with an atomic number of 78.

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?