Achild pushes a desk with a force of 15 n to the right. the desk accelerates to the right. which of the following statements correctly represents newton’s third law and the interaction between the child and desk?
the desk exerted slightly less than 15 n of force on the child, but the force is directed to the left.
the desk exerted exactly 15 n of force on the child, but the force is directed to the left.
the desk exerted slightly more than 15 n of force on the child, but the force is directed to the left.
the desk did not exert any force on the child.

Rank the torques on the five doors shown in the figure above from least to greatest. note that the magnitude of all the forces is the same

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?