A shop owner wanted to sell a gold-coloured cube to Mr Lee for $2000. The shop owner claimed that it was made of pure gold. Mr Lee wanted to investigate whether
the shop owner's claim was true. He measured the length and mass of the cube,
and found that it was 2 cm and 100 g respectively. He also found out that the density
of pure gold is 19.3 g/cm?State whether the shop owner's claim is true. Explain your answer. Is density a useful physical property for identifying an unknown substance? Explain why.

During spring semester at mit, residents of the parallel buildings of the east campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. a balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. assume that the stretching of the hose obeys hooke's law with a spring constant of 89.0 n/m. if the hose is stretched by 5.80 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length? unitst 3 number-1497 the tolerance is +/-5% open show work click if you would like to show work for this question:

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.

In the first law of thermodynamics, triangle e=q-w, what does q stand for