What is principal focus and focus length with examples​

Dalton’s model of an atom is the best described as a) a solar system b) a solid sphere c) a cloud d) a scoop of chocolate chip ice cream

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.

What is a view of science and psychology that says the value of knowledge depends on its usefulness? a. pragmatism b. psychotherapy c. physiology