A concussion, which is a form of mild traumatic brain injury, occurs after a blow to the head. The brain is surrounded by fluid and protective membranes called meninges, which usually cushion the brain. During an impact, the brain is pushed against the inside of the skull and can be bruised.
Sorry I'm so late, but I just took this test and the answer is white (for people who didn't study well ;) )
Answer:
- < 25 m/s
- triangle inequality
- between north and east
- 45° < angle < 60°
Explanation:
(a) Just as one-dimensional numbers add on a number line by putting them end-to-end, so two-dimensional numbers add on a coordinate plane the same way.
Here, we choose to let the positive y-axis represent North, and the positive x-axis, East. This is the way a map is conventionally oriented. The velocity of the plane is represented by a vector pointing north (up). Its length represents the magnitude of the velocity. Likewise, the wind is represented by a vector of length 15 pointing east (right). The sum of these is the hypotenuse of the triangle they form.
The magnitude of the sum can be found here using the Pythagorean theorem, but for the purpose of this question, you're not asked to find that.
Instead, you're asked to estimate whether it is more or less than 25 (m/s).
Your knowledge of the triangle inequality will tell you that the hypotenuse (resultant) must be shorter than the sum of the lengths of the sides of the triangle, hence must be less than 10+15 = 25.
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(b) The triangle inequality says the resultant is less than the sum of the other two sides of the triangle.
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(c) Since the wind is blowing the plane toward the east, but the plane is traveling toward the north, the resulting direction is somewhere between north and east.
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(d) "Somewhere between north and east" can be expressed as the inequality ...
0° < angle < 90°
Answer:
1.40625 kg-m^2
Explanation:
Supposing we have to calculate rotational moment of inertia
Given:
Mass of the ball m= 2.50 kg
Length of the rod, L= 0.78 m
The system rotates in a horizontal circle about the other end of the rod
The constant angular velocity of the system, ω= 5010 rev/min
The rotational inertia of system is equal to rotational inertia of the the ball about other end of the rod because the rod is mass-less

=1.40625 kg-m^2
m= mass of the ball and L= length of the ball