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3 years ago

What is the name of alfred wegener's hypothesis about moving land masses?

2 answers:

8 0

The name of Alfred Wegener's hypothesis about "moving land masses" is <u>Continental Drift</u>. He believed there was once a supercontinent which he called Pangea, which means "all land".

Umnica [9.8K]3 years ago

6 0

Pangaea; <span>the Greek word "pan" means "all" and Gaea or Gaia (or Ge) was the Greek name of the divine personification of the Earth. </span>

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The amount of kinetic energy an object has depends upon which of the following factors? I. the object's velocity II. the object'

harina [27]

1.) The object's Velocity

Faster it goes, more kinetic energy it has

8 0

3 years ago

1) A boy drags a wooden crate with a mass of 20 kg, a distance of 12 m, across a rough level floor at a constant speed of 1.5 m/

mojhsa [17]

Answer: a) 49.560 and 21.13 b) i) 50 N, ii) 196 N iii) 196 N iv) 47.685 N

c) i) 594.72 ii) 0 iii) 0 iv) 0

d) 594.72

Explanation: question a)

The force is inclined at an angle of 25° to the horizontal

The horizontal component of force = 50 cos 25° = 49.560 N

The vertical component of force = 50 sin 30°= 21.130N

Question b)

i) according to the question applied force is 50 N

ii) if g = 9.8m/s², w=mg where m = mass of object = 20kg hence weight = 20* 9.8 = 196 N

iii) the normal force is the force the floor exerts on the body as a result of the weight of the object.

Normal reaction R = W = mg, we already deduced that w = mg, hence R = 196 N.

iv) according to newton's laws of motion

F - Fr = ma

F = applied force = horizontal component of force = 49.560 N.

We need to get the acceleration (a) by using Newton laws of motion before we can be able to compute the frictional force..

The body started from rest hence initial velocity u = 0

Final velocity v = 1.5m/s distance covered (s) = 12m

v ² = u² + 2as

But u = 0

v² = 2as

1.5² = 2(a) * 12

2.25 = 24a

a = 2.25/24 = 0.09735m/s²

From F - Fr = ma

49.560 - Fr = 20 * 0.09735

49.560 - Fr = 1.875

Fr = 49.560 - 1.875

Fr = 47.685 N

Question c)

i) The applied force = 49.560 N, distance covered = 12m

Work done = force * distance

Work done = 49.560 * 12

Work done = 594.72 J

ii) the weight of the object does not make the object move a distance, hence work done = 0 ( since distance covered is 0)

iii) the normal force is the same thing as the weight and they did not cover any distance hence work done is zero.

iv) the frictional force does not cover any distance, hence work done is zero.

Question d)

The total work done = work done by applied force + work done by weight + work done by normal reaction + work done by frictional force.

Total work done = 594.72 + 0 + 0 + 0 = 594.72 J

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3 years ago

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Ilia_Sergeevich [38]

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3 years ago

Which of the following is true about light waves and sound waves? A. Sound waves can move at different speeds, but light waves a

vivado [14]

Answer:

Explanation:

Sound waves speed up noticeably when moving through a solid or liquid, because all it is is just particles colliding; and particles are way closer together with those states of matter.

The speed of light can change when moving through different substances, but this is dependent on complicated factors such as frequency, polarization, intensity, et. cetera

The important part is that it does change speed, so your answer is C.

Hope this helps!

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3 years ago

A proton and an electron traveling with the same velocity enter a uniform electric field. compared to the acceleration of the pr

kenny6666 [7]

The acceleration of the electron is larger than the acceleration of the proton.

The reason for this is that the mass of the electron is smaller (about 1000 times smaller) than the mass of the proton. The two particles have same charge (e), so they experience the same force under the same electric field E:
$F=eE$
However, according to Newton's second law, the force is the product between the mass particle, m, and its acceleration, a:
$F=ma$
which can be rewritten as
$a= \frac{F}{m}$
we said that the force exerted on the two particles, F, is the same, while the mass of the electron is smaller: therefore, from the last formula we see that the acceleration of the electron will be larger than that of the proton.

6 0

3 years ago