This is another one of those muddy misleading questions, followed by
a muddy group of choices from which an answer must be selected.
a). is absurd. There's no such thing as a "balanced force", only
a balanced group of forces.
b). is probably the choice the question is aiming for.
c). is not so. The engines of an airplane do plenty of work lifting the plane
off the ground, although the force of the engines is never directed upward.
d). is really awkward. The object's motion is almost never the cause of the force.
The force is almost always the cause of the object's motion.
Now for the big 800-lb gorilla in the room: No moving object needs to be involved
in order for energy to be flowing or work to be getting done.
-- A radio wave radiates through space. Straighten out a wire coat-hanger and
stick it up in the air where the radio wave can pass by it. Electrical current flows
through the wire, and you can drain the electrical energy out the bottom of it.
-- A light bulb is shining. Some distance away, something it's shining on
gets warm, because of the heat energy that has shot across to it from the
light bulb and soaked into it.
-- A lightning bolt jumps from the ground to a passing cloud. Or, if you feel
more comfortable with it, a lightning bolt jumps from a cloud to the ground.
It doesn't matter. Either way, there's enough energy splashing around to
ignite houses, zap TVs and computers, melt concrete, vaporize water, and
light up a city. Although nothing is moving.
Answer:
With a tape measure.
Explanation:
We can use a big tape measure, this tape is in the market and we can use the one with the proper length that lets us measure different sections of the total length of the pool.
Answer:
A. 148.23 m
B. 2.75 m/s
Explanation:
The following data were obtained from the question:
Time of flight (T) = 11 s
Maximum height (h) =?
Initial velocity (u) =?
Next, we shall determine the time taken for the ball to get to the maximum height. This can be obtained as follow:
Time of flight (T) = 11 s
Time (t) to reach the maximum height =.?
T = 2t
11 = 2t
Divide both side by 2
t = 11/2
t = 5.5 s
NOTE: Time to reach the maximum height is the same as the time taken for the ball to fall back to the plane of projection.
A. Determination of the maximum height to which the ball was thrown.
Time (t) to reach maximum height = 5.5 s
Acceleration due to gravity (g) = 9.8 m/s²
Maximum height (h) =?
h = ½gt²
h = ½ × 9.8 × 5.5²
h = 4.9 × 30.25
h = 148.23 m
B. Determination of the initial velocity.
Maximum height (h) reached = 148.23 m
Acceleration due to gravity (g) = 9.8 m/s²
Initial velocity (u) =?
u² = h/2g
u² = 148.23 / (2 × 9.8)
u² = 148.23 / 19.6
Take the square root of both side
u = √(148.23 / 19.6)
u = 2.75 m/s
Answer:
C. Targets
Explanation:
Because the Ad for the theme park effectively caught Raquel's attention, a businessperson would say that the ad accurately targeted Raquel. Marketers use specific colors, themes, designs, songs, etc to target a specific audience.
Answer:
<u>40 m/s</u>
Explanation:
The final velocity of an object that experiences a period of acceleration is given by:
v - vi = A*t
Initial velocity, vi, is = 20m/s
Acceleration, A, is 4m/2^2
Time, t, is 5 seconds
v - vi = A*t
v - 20m/s = (4m/2^2)/(5 sec)
v = (20 m/s) + (20 m/s)
v = 40 m/s
