*URGENT* Three sleds are attached to each other by a string and are being pulled over snow covered ground. The coefficient of kinetic friction between the sleds and snow is 0.20. They are being pulled with a force of 20. N. The first sled, m1, has a mass of 4.0 kg, the second sled, m2, has a mass of 1.0 kg, and the third sled, m3, has a mass of 1.0 kg. Find: a) the force of friction on

(i) m1

(ii) m2

(iii) m3

(iv) The total amount of friction in the system

b) the acceleration of the sleds.

c) the tension in the string A (i. e. the tension in the string connecting sled m1 and sled m2).

d) Upload a Free-body diagram of each sled as well as the system.

You have been consulted by the mobile phone company hookup about a new augmented reality product called “brows”. they want to develop an alternative to google glasses, which, you recall, is a proposed new product which plans to superimpose a whole range of wireless google services over the user’s ordinary vision of the world. these appear in little circles and ovals, and let you phone people, take photographs, navigate across cities and inside buildings, find shops and update your social media. brows would do this too, but not be limited to special google services. the user would wear a small cylinder-shaped device designed to fit on top of their existing eyewear (glasses or sunglasses). it would project a reversed image onto the inside of the lenses, the reflection of which would be in focus for the user. instead of voice control, the user would control the device by eye and neck movements, which the device would track. the device would connect via bluetooth to the user’s phone, which would supply most of the computing power and wireless connectivity. hookup also wants to know what existing services would be most in demand, and which would not work well with brows. using your knowledge of augmented reality, wearable technology and interface design, is the project feasible? if not, why not? if feasible, how could the product need to be modified for a better experience?

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f