4. Ano ang matinding suliranin ang kakaharapin kapag patuloy ang pagkasira ng lupa?
A. Maaaring magdulot ng kakulangan sa pagkain at panganib sa kalusugan
B. Maaaring magdulot ng kakulangan sa pangangailangan
C. Maaaring magdulot ng kawalan ng hanap-buhay sa mga mamamayan.
D. Pagkakaroon ng di inaasahang sakuna.

What is the role of lenses in microscopy?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?

Ahorizontal force of 400.0 n is required to pull a 1760 n truck across the floor at a constant speed. find the coefficient of sliding friction.