Explain why a magnet from your refrigerator could not be used to life something as heavy as a car ?

What is the mass of the water that is being heated? it requires 2,500 joules to raise a certain amount of water (c = 4.186 jig c) from 20.0°c to 60.0°c. o 159 o 40 g o 63 g o 80 g

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*

Roger pushes a box on a 30° incline. if he applies a force of 60 newtons parallel to the incline and displaces the box 10 meters along the incline, how much work will he do on the box? a. 5.2 × 102 joules b. 6.0 × 102 joules c. -5.2 × 102 joules d. -6.0 × 102 joules