<h3>
Answer: D) 30</h3>
Angle of incidence always equals angle of reflection. Think of a tennis ball being hit into a wall. The ball will bounce off at the same angle that it approached with. The angles mentioned are formed through the line called the "normal", which is the line perpendicular to the surface.
The correct answer is
<span>c) very small and very large
Let's see this with a few examples:
1) if we have a very small number, such as
</span>

<span>we see that we can write it easily by using the scientific notation:
</span>

<span>2) Similarly, if we have a very large number:
</span>

<span>we see that we can write it easily by using again the scientific notation:
</span>

<span>
</span>
Answer:
The change in temperature, 
Explanation:
Given that,
The temperature in Spearfish, South Dakota, rose from
in just 2 minutes. We need to find the temperature change in Celsius degrees. Change in temperature is given by final temperature minus initial temperature such that,

The relation between degrees Celsius and degrees Fahrenheit is given by :

Here, F = 49 degrees

So, the change in temperature is 9.45 degree Celsius. Hence, this is the required solution.
Answer:D
Explanation:according to the law of conservation of energy/momentum, when two bodies collides, their total momentum and energy before and after collision are equal. Given that the two bodies move with the same velocities after collision, means that the law has not been violated since momentum = mass x velocity (where mass is constant)
Answer:
200 N
Explanation:
The crowbar is 2 meter, or 200 cm. The effort arm is 160 cm, so the moment arm of the object is 40 cm.
(800 N) (40 cm) = F (160 cm)
F = 200 N