Test questions measure recall; matching concepts with their definitions measures recognition.
<u>Explanation:
</u>
According to Psychology our brain remembers everything what we learn but the understanding and remembering the right answer for the right question needs training and understanding ability. So in order to enhance the ability of recalling and recognizing among the students, the concept of test questions and matching with definitions are used in curricular activities.
As the students will be learning different terms, definitions, methods and different subjects, they should be able to distinguish among different definitions as well as they should recall the things they have learnt. So the answers for the test questions will help to recall the topics learnt by the students while the matching concept will help the students to recognize each definition with their terms.
Answer:
<em>1.Magnetic Force - Used in cranes to separate metal junk from junkyards.</em>
<em>2.Frictional Force- Helps us to walk.</em>
Resistors and reactors, for use over 600 volts, shall not be installed in close enough proximity to combustible materials to constitute a fire hazard and shall have a clearance of not less than<u> 300 mm </u>from combustible materials.
Explanation:
- The hazards associated with high power industrial resistors are primarily due to their open construction, which is necessary for cooling.
- The exposed conductors which make up the resistors can be not only a shock hazard but also a thermal burn hazard.
- When a resistor fails, it either goes open or the resistance increases. When the resistance increases, it can burn the board, or burn itself up.
- Avoid touching non-flammable resistors in operation; the surface temperature ranges from approximately 350 °C to 400°C when utilized at the full rated value. Maintaining a surface temperature of 200°C or less will extend resistors service life.
- Do not apply power to a circuit while measuring resistance. When you are finished using an ohmmeter, switch it to the OFF position if one is provided and remove the leads from the meter.
- Always adjust the ohmmeter for 0 (or in shunt ohmmeter) after you change ranges before making the resistance measurement.
Given data
*The given mass of the rock is m = 2 kg
*The given potential energy is U_p = 407 J
(a)
The diagram of the energy bar graph is drawn below
(b)
If an object is at rest and has potential energy, once it starts to fall from its rest state then this potential energy is completely transferred to kinetic energy. This means that the magnitude of the kinetic energy is equal to the potential energy of the object.
The change in kinetic energy of the rock while falling to the ground is given as
(c)
The formula for the speed of the block is given as
![\begin{gathered} U_k=\frac{1}{2}mv^2 \\ v=\sqrt[]{\frac{2U_k}{m}} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20U_k%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%5C%5C%20v%3D%5Csqrt%5B%5D%7B%5Cfrac%7B2U_k%7D%7Bm%7D%7D%20%5Cend%7Bgathered%7D)
Substitute the known values in the above expression as
![\begin{gathered} v=\sqrt[]{\frac{2\times407}{2}} \\ =20.17\text{ m/s} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20v%3D%5Csqrt%5B%5D%7B%5Cfrac%7B2%5Ctimes407%7D%7B2%7D%7D%20%5C%5C%20%3D20.17%5Ctext%7B%20m%2Fs%7D%20%5Cend%7Bgathered%7D)
Hence, the speed of the object is v = 20.17 m/s
