After the box comes to rest at position x1, a person starts pushing the box, giving it a speed v1. when the box reaches position x2 (where x2> x1), how much work wp has the person done on the box? assume that the box reaches x2 after the person has accelerated it from rest to speed v1. express the work in terms of m, v0, x1, x2, and v1.

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

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?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.