Ashopper in a supermarket pushes a cart with a force of 35.0 n directed at an angle of 25.08 below the horizontal. the force is just sufficient to balance various friction forces, so the cart moves at constant speed. (a) find the work done by the shopper on the cart as she moves down a 50.0-m-long aisle. (b) the shopper goes down the next aisle, pushing horizontally and maintaining the same speed as before. if the friction force doesn’t change, would the shopper’s applied force be larger, smaller, or the same? (c) what about the work done on the cart by the shopper?

The discovery that the universe appears to be expanding led to a widely accepted theory called a.) the big bang theory b.) the doppler effect c.) hubble’s law d.) solar nebular theory e.) the seyfert theory

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?

What are two different ways you could find the value of a? explain these methods.