Answer:
Electric engines have efficiencies of roughly 90% whilst combustion engines about 10% to 30%. This is because combustion engines emit much more heat, which is always energy that is not used as work, and thus increases inefficiency.
Explanation:
When the volume is 450 cm3 so the boat will displace 450 g.
so we have 450 g - 14.5g = 435.5 left
so to get how many pennies can be added to the boat before it sinks can be determined by:
divided the mass for the one penny:
no.of Penny = 435.5 / 2.5g
= 174.2
∴ the boat will float with 174 pennies and will start to sink with 175
Answer:
When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises. When a substance is cooled, it loses thermal energy, which causes its particles to move more slowly and its temperature to drop.
Molar mass Mg = 24.3 g/mol
1 mole mg ------------ 24.3 g
?? moles mg --------- 4.75 g
4.75 x 1 / 24.3 => 0.195 moles of Mg
hope this helps!
Yes what the other person said can I plz get an thanks