4. A 0.2 kg ball rotates at a constant speed of 3 m/s on the end of 1.2 m long string. What is the centripetal force exerted on the object? Round the magnitude of your answer to the nearest tenths place.

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?

Explain why electric current cannot exist if a current doesn't have a voltage source.

Which of the following statements comparing electron microscopy and light microscopy is false? which of the following statements comparing electron microscopy and light microscopy is false? both the electron microscope and the light microscope use the same wavelengths for illumination. images produced by light microscopes can be in color, whereas electron microscope images are black and white unless they are artificially colored. the electron microscope has greater resolution than the light microscope. electron microscopes can allow examination of viruses and internal cell structures, whereas light microscopes are limited to objects that are 0.5 micrometers and larger. request answer