A ladder, of length 3m and mass 20kg leans against a smooth, vertical wall so that the angle between the horizontal ground and the ladder is 60. a) find the magnitude of the friction and normal reaction forces that act on the ladder, if it is in equilibrium
b) Find the minimum value of the coefficient or friction between the ladder and the ground

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

The electric potential v is constant everywhere within a certain region of space. which statement below is true? the choices are: the electric field is also constant (but not zero) within the region. a charged particle placed within the region will experience an electric force. the electric field is zero everywhere within the region. the electric field varies from place to place within the region.