Answer:
Yes. The fact that an object moves at constant velocity implies that its speed is also constant. Note that the converse statement isn't necessarily true.
Explanation:
Velocity is a vector. For two vectors to be equal to each other,
- their magnitudes (sizes) need be the same, and
- they need to point in the same direction.
In motions, the magnitude of an object's velocity is the same as its speed.
If the car moves with a constant velocity, that means that
- the magnitude of its velocity, the speed of the car, is constant;
- also, the direction of the car's motion is also constant.
In other words,
.
Note that the arrow here points only from the velocity side to the speed side. It doesn't point backward because knowing that the speed of an object is constant won't be sufficient to prove that the velocity of the object is also constant. For example, for an object in a uniform circular motion, the speed is constant but the direction keeps changing. Hence the velocity isn't constant.
Displacement is simply the change in position, or the difference in the final and initial positions:
Then
(a) ∆<em>d</em> = 5 m - 0 m = 5 m
(b) ∆<em>d</em> = 1 m - (-2 m) = 1 m + 2 m = 3 m
(c) ∆<em>d</em> = 2 m - (-2 m) = 2 m + 2 m = 4 m
(d) ∆<em>d</em> = 6 m - 2 m = 4 m
Answer: B. The south magnetic pole attracts the north pole of another magnet.
Explanation:
The correct statement below about the interaction between magnets, magnetic materials and charges is that the south magnetic pole attracts the north pole of another magnet.
We should note that a magnet typically consists of two poles which are the North Pole and the South pole. The opposite poles doesn't repel each other but attracts each other while same pole repels one another.
In this case, the North Pole will attract the South Pole while same magnetic piles repel e.g the North Pole will repel the North Pole.
Answer:
Done
Explanation:
The differences are significant. The main disadvantages of a pinhole camera compared to a modern camera are:
Proper exposure requires a trial and error approach.
Requires manual control of shutter speed (difficult to control)
Poor image quality (due to diffraction effects).
Long exposures (lead to blurry images if the subject moves).
Fixed aperture or f-stop.
Advantages include:
Large depth of field.
Inexpensive
Robust and nearly 100% reliable.
If used properly can create artistic effects.
