D. Write short answers.
1. Name the different types of forces.
2. What are simple machines?
3. Why is geothermal energy referred to as a renewable source of energy?
4. From where does most of the heat energy come?
5. Name four different forms of energy.
E. Answer these questions.
1. What is a lever? On what basis are levers classified?
2. What is an inclined plane? How is it useful for us?
3. Does a screw join two pieces of wood better than a nail? How?
4. What does the law of conservation of energy state?
5. How is wind energy more environment friendly than heat energy?
Answers
Answer:
D
- Applied Force.
- Gravitational Force.
- Normal Force.
- Frictional Force.
- Air Resistance Force.
- Tension Force.
- Spring Force.
2.Simple machine, any of several devices with few or no moving parts that are used to modify motion and force in order to perform work. The simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw.
3.Because its source is the almost unlimited amount of heat generated by the Earth's core. Even in geothermal areas dependent on a reservoir of hot water, the volume taken out can be reinjected, making it a sustainable energy source.
4.sun
5.There are many forms of energy: like solar, wind, wave and thermal to name a few, but the 6 Forms of Energy we study in Needham are: Sound, Chemical, Radiant, Electric, Atomic and Mechanical. Sound Energy- is produced when an object is made to vibrate. Sound energy travels out as waves in all directions
E
1.Levers are classified by the relative positions of the fulcrum, effort and resistance (or load). It is common to call the input force the effort and the output force the load or the resistance
2.Inclined planes are widely used to move heavy loads over vertical obstacles; examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade.
3.Screws, on the other hand, may not be as forgiving, but their threaded shafts hold better in wood and draw boards together much more tightly and they have greater tensile strength. Screws also do a better job of holding tight during wood's natural expansion and contraction
4.Conservation law, also called law of conservation, in physics, several principles that state that certain physical properties (i.e., measurable quantities) do not change in the course of time within an isolated physical system.
5.Wind is an emissions-free source of energy
Wind is an emissions-free source of energyOverall, using wind to produce energy has fewer effects on the environment than many other energy sources. Wind turbines do not release emissions that can pollute the air or water (with rare exceptions), and they do not require water for cooling.
hope these answers help u ....pls mark me as brainliest...