Um corpo de massa m desliza sobre um plano horizontal com
velocidade constante. Sabendo que existe uma força de atrito
cujo coeficiente de atrito é = 0,5 entre o corpo e o plano e
após ter percorrido uma distância de 20m, o trabalho da força
de atrito foi de W= –2000J. Considerando que g = 10m/s2
,
podemos afirmar que a massa m em quilogramas do corpo é de
a) 50
b) 200
c) 20
d) 25
e) 40

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.

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?