John pushes his brother Danny on a skateboard. John applies a force of 39 N and Danny's acceleration is 0.9 m/s2. What is the combined mass of Danny
and his skateboard?
A. 43 kg
B. 48 kg
C. 31 kg
D. 35 kg

Identify which properties could correspond to solids, plasmas, or both. maintain a unique shape. collide infrequently with other particles. have very high velocities. conduct electricity. protons. have a low temperature. has long-range order.

Based on the equation and the information in the table, what is the enthalpy of the reaction?

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced.be sure your answer has the correct number of significant digits.