Temperatura aerului dintr‑o cameră de volum V = 40 m3 este t1 = 25 °C. În cameră se aduce un vas de capacitate calorică C = 400 J/K, ce conține o masă de gheață m = 500 g, la temperatura t2 = –10 °C. Considerând sistemul izolat, căldura specifică a gheții cg = 2 100 J/kg·K, căldura specifică a aerului c = 1 006 J/kg·K, densitatea medie a aerului rho = 1,29 kg/m3, determină temperatura aerului din cameră la stabilirea echilibrului termic.

If a spring has a k value of 100 newtons per meter and it is stretched 0.50 meters, what is the restoring force of the spring?

Atoaster oven has a resistive heating element. the average rate at which it dissipates energy as thermal energy is 1.00 \(\rm kw\). in the united states, emf amplitude in household circuits is \(\mathcal e_{\max}\) = 170 \({\rm \; v}\) and the \(\rm ac\) oscillation rate is 60 \(\rm hz\). part a what is the root-mean-square current through the heating element?

Afaulty model rocket moves in the xy-plane (the positive y direction is vertically upward). the rocket's acceleration has components ax(t) = ? t2 and ay(t) = ? ? ? t, where ? = 2.50 m/s4 , ? = 9.00 m/s2 , and ? = 1.40 m/s3 . at t = 0 the rocket is at the origin and has velocity ~v0 = v0x ? i + v0y ? j with v0x = 1.00 m/s and v0y = 7.00 m/s. (a) calculate the velocity and position vectors as functions of time. (b) what is the maximum height reached by the rocket? (c) sketch the path of the rocket. (d) what is the horizontal displacement of the rocket when it returns to y = 0?