I think A which is 4in but not sure
The equation for density is:
To help you remember - my teacher told us to remember "We <span>♡ density," and the heart stands for </span>
, or
. Cheesy, but it works!<span>
</span>
Back to the problem:We know the mass if 49g and the volume is 7
, so plug these values into the equation for density:
Answer: The density is 7 g/
I think it would have crystal formations if I remember correctly.
Sadly, after giving all the necessary data, you forgot to ask the question.
Here are some general considerations that jump out when we play with
that data:
<em>For the first object:</em>
The object's weight is (mass) x (gravity) = 2 x 9.8 = 19.6 newtons
The force needed to lift it at a steady speed is 19.6 newtons.
The potential energy it gains every time it rises 1 meter is 19.6 joules.
If it's rising at 2 meters per second, then it's gaining 39.2 joules of
potential energy per second.
The machine that's lifting it is providing 39.2 watts of lifting power.
The object's kinetic energy is 1/2 (mass) (speed)² = 1/2(2)(4) = 4 joules.
<em>For the second object:</em>
The object's weight is (mass) x (gravity) = 4 x 9.8 = 39.2 newtons
The force needed to lift it at a steady speed is 39.2 newtons.
The potential energy it gains every time it rises 1 meter is 39.2 joules.
If it's rising at 3 meters per second, then it's gaining 117.6 joules of
potential energy per second.
The machine that's lifting it is providing 117.6 watts of lifting power.
The object's kinetic energy is 1/2 (mass) (speed)² = 1/2(4)(9) = 18 joules.
If you go back and find out what the question is, there's a good chance that
you might find the answer here, or something that can lead you to it.
We want 4/5 of a number to be 144. This means that
Multiplying both sides by 5/4, we have
