Two boys want to move the chair by applying two forces perpendicular to each other, of module F1 = 65 N and F2 = 83 N. Another boy applies a force F3 to the chair which opposes the movement and keeps it steady. Calculate the angle of inclination of the resultant of F1 and F2. What is the form, direction and direction of F3?

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

Acalorimeter uses the principle that thermal energy flows from hotter material to colder material until both reach the same

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative