Answer:
Explanation:
Lift occurs when a moving flow of gas is turned by a solid object. The flow is turned in one direction, and the lift is generated in the opposite direction, according to Newton's Third Law of action and reaction. Because air is a gas and the molecules are free to move about, any solid surface can deflect a flow.
In this item, there needs to be a basis as to how many significant numbers can be present in a certain figure. If the answer 327.66 m/s is to be expressed as a 3 significant figures only, the answer would have to be 328. What was done here is to simply round up the units digit of the number since the decimal place (tenths) digit has a value of greater than 4.
The answer to this item is therefore letter B.
Answer:
A) J= 398 A/m²
B) E= 1.6×10⁶ N/C
C) P= ×10⁴ W
Explanation:
My work is in the attachment. Comment with questions or if something seems wrong with my work. (Honestly, they seem little high but it could just be the given numbers being unrealistic.) Below I have explanations of each part to match up with the image as well.
Part A:
Current density (J) is defined as the amount of current in a particular cross-sectional area. To get this, we simply need to divide the current (I) by the cross-sectional area of the electron beam tube (A).
Part B:
This one took the most work for me. I used a kinematic equation (yes they apply to electrons) to find the electric field (E). I used a modified form of the familiar: ∆d=V₀τ+aτ²/2
We can use the fact that τ= V/a, a=(qE/m), and V₀=0 here to rewrite the equation in terms of values we know and/or can look up. From there we solve for E and plug in the values.
Part C:
Power (P) is simply work (W) over time (τ). We know what τ is from before and can take W= mV²/2. Plugging these in and reducing some values gives us an equation for power as well.
<span>We can draw a free body diagram for one of the boxes.
There are two forces acting on the box.
The downward force is the force of gravity which is 50 N.
The upward force is the force from the tension in the rope.
Since the box is suspended, it is not accelerating.
Therefore, the net force must be zero.
Therefore the tension in the rope must be 50 N.</span>
7). Stopping is an acceleration.
2nd law . . . . . f = m a
Bigger mass needs more force.
Bowling ball has more mass than a golf ball.
9). 2nd law . . . . . f = m a
It doesn't say anything about where the force comes from,
only the size of the force. A child, dog, bird, adult, or
tow-truck have to use the same amount of force to produce
the same result.
10). 2nd law . . . . . f = m a
More acceleration requires more force.
