Aworker stands still on a roof sloped at an angle of 35° above the horizontal. he is prevented from slipping by static frictional force of 560 n. find the mass of the worker.

Which quantities are scalars? choose all that apply a.distance b.speed c. acceleration d.velocity

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

When does your body conduct current more readily?