Helping verbs come before the main verb, the main verb in the sentence is repair therefor the helping verb would be could.
Answer:
Part a)

Part b)
t = 12 s
Explanation:
Part a)
Tension in the rope at a distance x from the lower end is given as

so the speed of the wave at that position is given as

here we know that

now we have


Part b)
time taken by the wave to reach the top is given as




The answer is A
Materials that are good conductors of thermal energy are called thermal conductors. Metals are very good thermal conductors. Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators
Answer:heed
Explanation:
heed knows how to divide.