Imagine that you have just purchased a coffee in a cup, with a lid. you place your coffee cup on a table and it starts to cool down. we are going to model this cooling process. choose whatever type of coffee cup you are most familiar with.
* once the sides have warmed up, calculate the outside surface temperature of the sides of the cup, and the heat flow through the sides of the cup. you may neglect radiation from the outside of the cup.
the specific heat capacity of water (and coffee) is around 4200 j kg-1 k-1. cardboard has a thermal conductivity of around k ~ 0.025 w m-2 k-1 , a density of around 700 kg m-3 and a specific heat capacity of around 1400 j kg-1 k-1. glass has a thermal conductivity of around k ~ 1 w m-2 k-1, a density of around 2500 kg m-3 and a specific heat capacity of around 700 j kg-1 k-1. styrofoam (foamed plastic) has a thermal conductivity similar to air and a density of around 50 kg m-3, while hard plastics have thermal conductivities of k ~ 0.025 w m-2 k-1 and densities similar to water: both have specific heat capacities of around 1500 j kg-1 k-1.

Aplane flies a distance d from west to east at a constant speed vp , with respect to the air in a time twe . on the return trip, the plane flies a distance d from east to west at a constant speed vp , with respect to the air in a time tew . on both trips the wind blows from west to east at a constant speed va , with respect to the ground 1) what is tew in terms of vp, va, and d, as needed? tew=dvp tew=dvp+va tew=dva tew=dvpâ’va tew=12dvp tew=12dvp+va tew=12dvpâ’va your submissions: b submitted: saturday, january 26 at 6: 49 pm feedback: feedback will be given once all questions have been attempted and the grade cluster button has been pressed. 2) what is twe in terms of vp, va, and d, as needed? twe=dvp twe=dvp+va twe=dva twe=dvpâ’va twe=12dvp twe=12dvp+va twe=12dvpâ’va your submissions: d submitted: saturday, january 26 at 6: 49 pm feedback: feedback will be given once all questions have been attempted and the grade cluster button has been pressed. 3) assuming d = 2300 miles, vp = 400 miles/hr, and twe = 4 hours, what is va, the speed of the wind with respect to the ground? va = 100 miles/hr va = 575 miles/hr va = 200 miles/hr va = 175 miles/hr va = 975 miles/hr 4) once again, assuming d = 2300 miles, vp = 400 miles/hr, and twe = 4 hours, what is tew, the time it takes the plane to fly a distance d miles from east to west? tew = 5.75 hours tew = 11.5 hours tew = 7.67 hours tew = 8 hours tew = 10.2 hours

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?