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3 years ago

Can someone please help me with science.

Physics

1 answer:

pav-90 [236]3 years ago

8 0

On the dog's return trip (between <em>t</em> = 10 and <em>t</em> = 12.5 seconds), the slope of the position function is steeper than during the first 5 seconds, which means the dog ran home faster. The only option that captures this is D.

You can check to make sure that the dog indeed runs twice as fast on the return trip. The slope of the position function during the first 5 seconds is

(change in position) / (change in time) = (5 - 0) / (5 - 0) = 5/5 = 1

while during the return trip, it is

(0 - 5) / (12.5 - 10) = -5/2.5 = -2

Ignoring the sign (which only indicates the direction in which the dog was running), we see that the dog's speed on the return trip was indeed twice as high as during the first 5 s.

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Alex is standing still and throws a football with a speed of 10 m/s to his friend, who is also standing still. The two friends a

Phantasy [73]

The question is incomplete. It comes with a set of answer choices.

These are the answer choices:

Alex observes it as 10 m/s, and his friend observes it as less than 10 m/s.

Alex observes it as less than 10 m/s, and his friend observes it as 10 m/s.

Both Alex and his friend observe it as 10 m/s.

Both Alex and his friend observe it as less than 10 m/s.

Answer: Both Alex and his friend observe it as 10 m/s.

Justification:

1) The speed is relative to the frame of reference.

2) It is said that the both Alex and his friend are standing still.

3) Then, the speed they both see is the same, 10 m/s, respect the Earth (where they are standing still).

Of course, Alex is watching the ball moving away and his friend is seing it approaching, but it is not relevant for the question, as it deals with the speed which is only about magnitude, not direction.

7 0

3 years ago

Read 2 more answers

How much energy is required to raise the temperature of 5g of air by 10°C?

Alex777 [14]

You need to know the specific heat capacity of air.
Then energy needed = 0.005 x sp.heat.cap x 10

4 0

3 years ago

An elevator filled with passengers has a mass of 1603 kg. (a) The elevator accelerates upward from rest at a rate of 1.20 m/s2 f

Galina-37 [17]

Answer:

T = 17649.03 N = 17.65 KN

Explanation:

The tension in the cable must be equal to the apparent weight of the passenger. For upward acceleration:

$T = W_A = m(g+a)\\$

where,

T = Tension in cable = ?

$W_A$ = Apparent weight

m = mass = 1603 kg

g = acceleration due to gravity = 9.81 m/s²

a = acceleration of elevator = 1.2 m/s²

Therefore,

$T = (1603\ kg)(9.81\ m/s^2+1.2\ m/s^2)\\\\$

8 0

3 years ago

In a transformer, energy is carried from the primary coil to the secondary coil by:________

likoan [24]

In a transformer, energy is carried from the primary coil to the secondary coil by magnetic field in the iron core.

To find the answer, we have to know more about the transformer.

<h3>How transformer works?</h3>

An item utilized in the transfer of electric energy is a transformer.
AC current is used for transmission.
It is frequently used to modify the supply voltage between circuits without altering the AC frequency.
The fundamentals of mutual and electromagnetic induction govern how the transformer operates.
Magnetic field through the primary coil changes when primary coil current varies. the iron core of the secondary coil likewise has a magnetic field.
EMF is therefore generated in the secondary coil.

Thus, we can conclude that, in a transformer, energy is carried from the primary coil to the secondary coil by magnetic field in the iron core.

Learn more about the transformer here:

brainly.com/question/26787198

#SPJ4

5 0

2 years ago

What is your theory on frame of reference?

____ [38]

What is your theory on frame of reference?

Answer:

It is the idea of seeing something from a different perspective

Explanation:

Hope this helps!

8 0

3 years ago