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g100num [7]
3 years ago
9

49. A block is pushed across a horizontal surface with a

Physics
1 answer:
nata0808 [166]3 years ago
8 0

Answer:

(a) 37.5 kg

(b) 4

Explanation:

Force, F = 150 N

kinetic friction coefficient = 0.15

(a) acceleration, a = 2.53 m/s^2

According to the newton's second law

Net force = mass x acceleration

F - friction force = m a

150 - 0.15 x m g = m a

150 = m (2.53 + 0.15 x 9.8)

m = 37.5 kg

(b) As the block moves with the constant speed so the applied force becomes the friction force.

F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4

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While John is traveling along an interstate highway, he notices a 150 mi marker as he passes through town. Later John passes a 1
Lerok [7]

Answer:

Part a)

distance = 112 miles

Part b)

current position = 112 miles from the position of town

Explanation:

Part a)

Since the distance marker is showing the distance between the town and the position of john at all time

so here we have

d = 112 miles

Part b)

Current position of John is given as

r = 112 miles

from the position of the town

7 0
3 years ago
Read 2 more answers
Whats the answer<br> ----------------------------
GenaCL600 [577]

Answer:

repel each other

Explanation:

The magnitude of the charge of an electron is called... ... If a positively-charged glass rod is suspended so that it turns easily and another positively-charged glass rod is brought close to it, the two rods will... Repel each other.

8 0
2 years ago
A college student holds a pail full of water by the handle and whirls it around in a vertical circle at a constant speed. The ra
Pavlova-9 [17]

The minimum speed of the water must be 3.4 m/s

Explanation:

There are two forces acting on the water in the pail when it is at the top of its circular motion:

  • The force of gravity, mg, acting downward (where m is the mass of the water and g the acceleration of gravity)
  • The normal reaction, N also acting downward

Since the water is in circular motion, the net force must be equal to the centripetal force, so:

N+mg=m\frac{v^2}{r}

Where:

g=9.8 m/s^2

v is the speed of the pail

r = 1.2 m is the radius of the circle

The water starts to spill out when the normal reaction of the pail becomes zero:

N = 0

When this occurs, the equation becomes:

mg=m\frac{v^2}{r}\\v=\sqrt{gr}

And substitutin the values of g and r, we find the minimum speed that the water must have in order not to spill out:

v=\sqrt{(9.8)(1.2)}=3.4 m/s

Learn more about circular motion:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

6 0
3 years ago
1. Have you ever tried to undergo an X- ray to test on youur body? What can you see in the fiom after the examination? Why is th
liraira [26]

Answer:

1) λ < 2d,  2)  nfrared imaging technique, 3) each color there is a different index of refraction

Explanation:

We are going to answer the three questions

1) When x-rays pass through matter in order to be dispersed, their wavelength must be of the order of the length of separation in the atoms and molecules of the body, in solid bones this length is similar and they scatter and reflect the x-rays therefore they can be observed, the fat and the soft tissue have a much greater separation therefore the x-rays cannot be reflected and consequently it is not observable by this technique.

2) At airports they use the infrared imaging technique, where the image is taken for the infrared wavelength, which is the heat part of the electromagnetic spectrum; consequently, when the image is viewed, the hottest areas appear brighter and, since when a person has a virus, his temperature rises, his temperature rises, it is possible to observe people with a higher temperature.

3) when white light hits a prism it is refracted with the equation

            n₁ sin θ₁ = n₂ sin θ₂

where the incidence of refraction depends on the wavelength, therefore for each color there is a different index of refraction and consequently the light is separated in its different colors.

5 0
2 years ago
Which would BEST describes what occurs when a ball is thrown against a wall? A) The ball will not bounce off the wall. B) The ba
oee [108]

Answer:

D) The ball exerts a force on the wall and the wall exerts a force back.

Explanation:

Newton's third law of motion states that:

"When an object A exerts a force on another object B, then object B exerts an equal and opposite force on object A"

In this problem, we can identify (for instance) object A with tha ball and object B with the wall. Therefore, if we apply Newton's third law, we get:

The ball (object A) exerts a force on the wall (object B), therefore the wall (object B) exerts an equal and opposite force on the ball (object A). So, option D is the correct one.

3 0
3 years ago
Read 2 more answers
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