An object of mass 100 kg is initially at rest on a horizontal frictionless surface. at time t = 0, a horizontal force of 10 n is applied to the object for 1 s and then removed. which of the following is true of the object at time t = 2s if it is still on the surface?
(a) it is at the same position it had at t 0, since a force of 10 n is not large enough to move such a massive object.
(b) it is moving with constant nonzero acceleration.
(c) it is moving with decreasing acceleration.
(d) it is moving at a constant speed
(e) it has come to rest some distance away from the position it had att 0.

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?

Road users moving into your lane, brake lights, and abrupt changes in road surface are a. rare at night b. indicators of potential hazards c. not worth worrying about before you reach them d. no problem for experienced drivers

Who was the first scientist to measure speed as distance over time?