Let's use Newton's 2nd law of motion:
Force = (mass) x (acceleration)
Force = (68 kg) x (1.2 m/s²) = 81.6 newtons .
Answer:
The difference between the two is, well for one
Spectrum: The entire range that the "waves" could be such, as visible light, x-ray's and so on.
Waves: These are different because they aren't telling you or showing the entire spectrum just which they length that they are.
It may confuse you but it makes sense to me (Sorry)
Explanation:
The emerging velocity of the bullet is <u>71 m/s.</u>
The bullet of mass <em>m</em> moving with a velocity <em>u</em> has kinetic energy. When it pierces the block of wood, the block exerts a force of friction on the bullet. As the bullet passes through the block, work is done against the resistive forces exerted on the bullet by the block. This results in the reduction of the bullet's kinetic energy. The bullet has a speed <em>v</em> when it emerges from the block.
If the block exerts a resistive force <em>F</em> on the bullet and the thickness of the block is <em>x</em> then, the work done by the resistive force is given by,

This is equal to the change in the bullet's kinetic energy.

If the thickness of the block is reduced by one-half, the bullet emerges out with a velocity v<em>₁.</em>
Assuming the same resistive forces to act on the bullet,

Divide equation (2) by equation (1) and simplify for v<em>₁.</em>

Thus the speed of the bullet is 71 m/s
Answer:
$900 trillion
Explanation:
If Alaska is 20% of the contiguous US, then the approximate area of interest is ...
1200 miles × 3000 miles = 3.6×10^6 square miles.
The size of a dollar bill is about ...
(6.5 cm)·(15.5 cm) = 100.75 cm^2
One mile is 160,934.4 cm, so 1 square mile is about ...
1 mi^2 = (160,934.4 cm)^2 ≈ 2.59·10^10 cm^2
The number of dollars of interest is then ...
(3.6 · 10^6 mi^2)(2.59 · 10^10 cm^2)/(100.75 cm^2) ≈ 9.3·10^14
≈ 930 × 10^12 . . . dollars
It would cost about 900 trillion dollars to cover the land area of the US in $1 bills.
Answer:
Steel
Explanation:
Mass is density times volume.
m = ρV
Since they have the same size and shape, they have the same volume.
Steel has a higher density than Styrofoam, so at the same volume, the steel ball will have more mass.