Multiple choice: Sunspots appear dark because (a) they are patches of the photosphere that occasionally burn up, creating soot;
(b) the changing magnetic polarity of the Sun causes gas in the sunspot to cool down substantially;
(c) they are regions in which strong magnetic fields make it difficult for fresh supplies of hot, ionized gas to reach the photosphere;
(d) they are much hotter than the surrounding area, so their emission peaks at ultraviolet wavelengths, which our eyes cannot see; or
(e) they are holes in the photosphere through which the cooler interior of the Sun is visible.

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.

The softest and hardest minerals are: softest hardest

An object's buoyant force and weight mean the same thing. a. trueb. false