Answer:
There are different ways to investigate density. In this required practical activity, it is important to:
record the mass accurately
measure and observe the mass and the volume of the different objects
use appropriate apparatus and methods to measure volume and mass and use that to investigate density
Explanation:
Answer:
D. because the light is reflected back into the fiber along its sides
Explanation:
The fiber is constructed in a way that the light is bent/reflected/refracted toward the center core of glass. So, from the center core, there is a layer above it that has a different propagation than the core, and above that the same thing. To give you a real world visual example, if you look down in a pool of water, then stick a straight stick into it, you see that the straight stick appears to bend. That is what is happening to the light as it travels through a different medium (air to water). This same effect is incorporated in the fiber optic cable construction.
The body systems that help cells get the energy they need are the digestive system and circulatory system. The first system is the digestive system because when you eat food, your body breaks it down using the stomach and other different parts of the digestive system. The next one is the circulatory system because your blood carries the nutrients you acquired from food you digested to the cells throughout your body.
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