Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering- resistant rocks, such as quartzite, given the right conditions.
Answer:
A. a material burns out when current is excessive
Yes it is. Uh huh, uh huh, shore enuff. Mmm hmm. Yeah yeah yeah. Yah Mon ! Indubitably.
Answer:

Explanation:
Given
See attachment for the graph
Required
Determine the frequency
Frequency (F) is calculated as:

Where
T = Time to complete a period
From the attachment, the wave complete a cycle or period in 3 seconds..
So:


--- Approximated
'Doing work' is a way of transferring energy from one object to another, energy is transferred when a force moves through a distance.
If i explain with formula
Work done (J) = Energy transferred (J)
So more energy, more work done bc u transferred more energy to move the object and doing the work. and if you only use a little of energy, the work done also only a little.