A copper wire of radius 2.4mm is fixed to a ceiling. When a load of 100 kg
is suspended at its lower end, it is extended by 1.5 mm. If the Young's
modulus of copper is 1.2 x 1011Nm?, calculate the length of the wire.

How much work is done lifting a 9.10 kg box straight up onto a shelf that is 1.80 m high?

Jackson is designing a new heater, and he wants to experiment with different thermally conductive materials. which of these materials would be useful in conducting heat?

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.