One of the challenges of tidal wave energy is: the start-up costs are expensive. the materials needed to couple the tidal energy to electricity are rare. the tides are very unpredictable. as global warming increases, the tides will diminish.

One of the challenges of tidal wave energy is the start-up costs are expensive. Because it needs materials that do not erode quickly and can withstand the pressure of the incoming waves. This is another form of a renewable source of energy.

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg

the answer is ampere

the ampere is used to measure electricity. an ampere is a unit of electric current equal. a unit of measure for the flow of current in a circuit. one ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance.