The intensity of sunlight at the earth's surface is 9es w/m2. assuming a wavelength of 579 nm, how many photons pass through the eye of a neede in one second? assume the needle eye is circular, with a radius of 0.596 mm, and that the plane of the circle is perpendicular to the light rays

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 graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

If a tank filled with water contains a block and the height of the water above point a within the block is 0.8 meter, what is the pressure at point a?