Physics, 05.08.2019 02:00 4300252063
After 15 minutes, 30 g of a sample of polonium-218 remain unchanged. if the original sample had a mass of 960 g, what is the half-life of polonium-218?
Answers: 1
Physics, 21.06.2019 22:30
Acricket ball of 70g moving with a velocity of 0.5 m/s is stopped by a player in 0.5s what is the force applied to stop the ball
Answers: 1
Physics, 22.06.2019 06:20
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?
Answers: 1
Physics, 22.06.2019 13:40
Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these
Answers: 1
Physics, 23.06.2019 01:30
Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. which of the following best describes how such a telephone is able to transmit and receive information? a. the cellular telephone transmits, receives, and encodes information using only sound waves. b. the cellular telephone transmits, receives, and encodes information using only electromagnetic waves. c. the cellular telephone transmits information by electromagnetic waves to a receiver which then encodes them and produces sound. d. the cellular telephone transmits information by sound waves to a receiver which then encodes them and produces electromagnetic waves.
Answers: 2
After 15 minutes, 30 g of a sample of polonium-218 remain unchanged. if the original sample had a ma...
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Social Studies, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01
Mathematics, 30.07.2020 17:01