Answer:
9ms^2
Explanation:
since ,Force=mass*acceleration
then, acceleration=force/mass
and, Force=90N
Mass=10pound
therefore, acceleration=90/10
=9ms^2
Answer:
The efficiency is 0.33, or 33%.
Explanation:
From the thermodynamics equations, we know that the formula for the efficiency of a heat engine is:

Where η is the efficiency of the engine, Q_1 is the heat energy taken from the hot source and Q_2 is the heat energy given to the cold object. So, plugging the given values in the formula, we obtain:

This means that the efficiency of the heat engine is 0.33, or 33% (The efficiency of an engine is dimensionless).
Well, energy can be produced from the burning of fossil fuels which produce steam to spin turbines which generates electricity. But fossil fuels like coal and oil are no renewable.
Some renewable ways to get energy is water where they separate hydrogen from h2o because hydrogen can be made into energy. Also nuclear fission is another way to get energy. That's when in a nuclear power plant, the atoms nucleus is split which sends a large amount of energy.
Wind energy is another source of energy, which is from windmills. Another renewable energy source is solar energy. That's when u use solar cells, like some houses and calculators have, which generates a lot of energy, but only in the day since the sun doesn't shine in the nigh.
Hope I helped!!!
the layers of rocks, the ancient treasures that are at the bottom of the sea, how old the coral is. But I don't think they determined how old it is, how would the dinosaurs that lived in water swim or any drink water. I don't know if this helps but hopefully it does. Also scientist have made advanced tech that could help with the age determination of the ocean floor.