A stretch of 1 km new concrete pavement is being laid in a 100 mm thick layer. The ambient temperature when laying the concrete is 20°C, and you can assume that the concrete does not have any internal stress at this temperature. The thermal expansion coefficient of concrete is 10μm/m°C, and its elastic modulus is 20 GPa. Suppose all deformation of the concrete is restrained (the concrete cannot move), and suppose that the concrete behaves as a linear elastic material. Knowing its tensile strength is 10 MPa, at what temperature does this concrete crack?

While studying chemical reactions and conservation of matter, sarah's class conducted a variety of experiments. sarah and her lab partner found the mass of a wax candle and placed the candle in a flask. the students lit the candle and let it burn to completion. all that was left was wax and charred candle wick. per their teacher's instructions, the students found the mass of the products. their data can be seen in the data table. formulate a hypothesis the students could test to explain why the experiment did not support the law of conservation of matter. a) the students could repeat the experiment using different candles; there might have been a flaw in the candle. b) the experiment should be repeatable. the students should run several trials and then take an average of the after mass in each trial. c) the students should have someone in the class check their measurement skills as they repeat the experiment. they may have made an error using the balance. d) the students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed. submit

Which of the following compounds would be primarily ionic? methane, ch4, ammonia nh3, calcium chloride, cacl2, or carbon dioxide, co2

Macy always thought there were only a few hair colors blonde brown and black however when she actually began looking around she saw varying shades of these hair color what is a possible reason for so many different hair colors