Answer:
Review each answer in the explanation part
Explanation:
Identify a problem or need = Aerospace engineers need a lightweight material to build a jet
Note: Identify a problem is related always with a need.
After identify the problem the next stage is the design
Design a solution = Engineers determine what features the material must have.
Note: The design process implies the choice of the materials and the proper numeric calculations.
Implement the solution = Engineers test a carbon - plastic compound in a wind tunnel.
Note: after the design, the following process is the built of the equipment and the different tests.
Evaluate the solution = The carbon-plastic compound is redesigned to save maximun energy.
Note: After testing, you enter a part of re-design that means making improvements to the already constructed.
I'm not sure about the magnitude, but the direction of the normal force is upward.
Work is done when spring is extended or compressed. Elastic potential energy is stored in the spring. Provided inelastic deformation has not happened, the work done is equal to the elastic potential energy stored.
There is still air inside of a house, which is pushing the roof upwards, so the forces are equal and the roof is not crushed.
Answer A an Open Universe
The future of universe is predicted from space time curve. There are many possibilities solutions or outcomes which on plotting are classified as open, close, flat and curved. Open Universe is when universe is expanding and it will continue to expand forever. This is proved experimentally as well that universe is expanding using red and blue shift observations from various aspects.
