Can anyone pls answer these 2 for me? :)

Mike walks 100 meter north, then walks 30 meters south. after this, he walks another 10 meters north. what is the magnitude of his total displacement during this walk,in meters?

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n

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