
Explanation
the density of an object is given by:

Step 1
find the volume of the bar
a)find the volume of the rectangular bar.
the volume of a rectangular prism is given by:

replace

Step 2
now,
Let

replace in the formula

therefore, the answer is

I hope this helps you
Answer:
A star uses fusion as an energy source by building larger atoms from smaller atoms.
Explanation:
Nuclear fission and fusion are two processes at which an atomic nucleus is changed to produce energy. Fission is the process splitting heavy atomic into lighter atomic nuclei.
So, fusion is the combination of smaller atoms to form larger atoms and star uses this as source of energy.
Fusion is the process at which light atomic nuclei are merged or fused together to form heavier nuclei.
The energy source for all stars is nuclear fusion. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom.
Answer: C
Explanation: As the universe stretches it expands more and more the distance between each other. Hope this helps.
Answer:
See explanation
Explanation:
A change in momentum occurs when a force is applied to an object and changes its velocity.
Answer:
344Hz
Explanation:
First we need to more that the frequency will inky resonate in the portion not containing water. If the total length is 1m and the filled with water up to 75cm, the length of the air column will be 100cm - 75cm = 25cm
Fundamental frequency of a closed pipe fo = V/4L
V is the velocity of sound in air
L is the length of the air column
Given V = 344m/s
L = 25cm = 0.25m
fundamental resonant frequency = 344/4(0.25)
= 344/1
= 344Hz