Adouble pulley with friction is being used to lift a 50kg object at constant velocity. if the force needed is 300n, what is the efficiency and the actual mechanical advantage of the pulley? 0 a. efficiency = 0.6, mechanical advantage-2 o b. efficiency-0.83, mechanical advantage-2 ° c. efficiency = 0.6, mechanical advantage = 1.67 0 d. efficiency = 0.83, mechanical advantage-1.67

Abatter hits the baseball a with an initial velocity of v0 = 110 ft/sec directly toward fielder b at an angle of 23° to the horizontal; the initial position of the ball is 2.2 ft above ground level. fielder b requires 0.44 sec to judge where the ball should be caught and begins moving to that position with constant speed. because of great experience, fielder b chooses his running speed so that he arrives at the “catch position” simultaneously with the baseball. the catch position is the field location at which the ball altitude is 8.4 ft. determine the velocity of the ball relative to the fielder at the instant the catch is made.

The summit of chimborazo, in ecuador, which is at a distance of about 6,384 km from the earth’s center. the bottom of the mariana trench, in the western pacific ocean, which is nearly 6,370 km from the center of the earth. on the surface of earth on the equator line.

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine