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3 years ago

Help me please I’ve been stuck on this forever now ☹️

Physics

2 answers:

valina [46]3 years ago

7 0

C, velocity I believe this is the answer to your question

castortr0y [4]3 years ago

5 0

Hey ! If you've already been stuck on it forever, then
a few more days won't make that much difference.

No, I'm just kidding. I wouldn't do that to you.

I'm sure this is all stuff that you've heard before.
Here it is again, all in one place:
____________________________________

-- LOCATION . . . . . a point.
If you move from one point to another point, then you travel a

-- DISTANCE . . . . . the path you followed between two points.
If you're moving right now, then how fast you're moving is your

-- SPEED . . . . . the RATE of how fast your distance is changing.
If we also know what DIRECTION you're moving, then we know your

-- VELOCITY . . . . . your speed AND direction.
If your speed is changing OR your direction is changing, then you have

-- ACCELERATION . . . . . the RATE of how fast your speed or your direction is changing.
____________________________________

Go through it again, in the other direction:

Acceleration . . . the rate of how fast your velocity is changing.

Velocity . . . your speed AND your direction.

Speed . . . the rate of how fast your distance is changing.

Distance . . . the length of the path you walk from one place to another.
___________________________________

For the question on the screen:

Instantaneous acceleration describes how fast a velocity is changing
at a specific instant.

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What type of accidents are among the most common cause of serious work related injuries and deaths

Bezzdna [24]

Trips/slips/falls are among the most common types of work related injuries and/or deaths.

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3 years ago

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How high was a brick dropped from if if falls in 2.5 seconds?

jenyasd209 [6]

Using the kinematic equation d = V_0 * t + 1/2 * a * t^2, where d is height you can rewrite this to be d = 1/2*g*t^2 or 4.9t^2
g = a because this is a free fall
d = 1/2 * 9.81m/s^2 * 2.5^2
d = 30.65625m
d = 30.7m

7 0

3 years ago

You are sitting on a merry-go-round of mass 200 kg and radius 2m that is at rest (not spinning). Your mass is 50 kg. Your friend

Bogdan [553]

Answer:

a. $\tau=200J$ b. $\alpha=0.44 \frac{rad}{s^2}$ c. $\alpha=0.33\frac{rad}{s^2}$ d. The angular acceleration when sitting in the middle is larger.

Explanation:

a. The magnitude of the torque is given by $\tau=rF\sin \theta$ , being r the radius, F the force aplied and $\theta$ the angle between the vector force and the vector radius. Since $\theta=90^{\circ}, \, \sin\theta=1$ and so $\tau=rF=2m100N=200Nm=200J$ .

b. Since the relation $\tau=I\alpha$ hols, being I the moment of inertia, the angular acceleration can be calculated by $\alpha=\frac{\tau}{I}$ . Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is $I=\frac{1}{2}Mr^2$ , being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by $I_p=m_pr_p^{2}$ , being $m_p$ the mass of the person and $r_p^{2}$ the distance from the person to the center. Given all of this, we have

$\alpha=\frac{\tau}{I}=\frac{\tau}{I_{disk}+I_{person}}=\frac{Fr}{\frac{1}{2}Mr^2+m_pr_p^{2}}=\frac{200Nm}{\frac{1}{2}200kg*4m^2+50kg*1m^2}=\frac{200\frac{kgm^2}{s^2}}{450Nm^2}\approx 0.44\frac{rad}{s^2}$ .

c. Similar equation to b, but changing $r_p=2m$ , so

$alpha=\dfrac{200\frac{kgm^2}{s^2}}{\frac{1}{2}200*4kg\,m^2+50*4 kg\,m^2}=\dfrac{200}{600}\dfrac{1}{s^2}\approx 0.33 \frac{rad}{s^2}$ .

d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.

5 0

3 years ago

If the angular velocity of the pully is -8.4rad/s at a given time, and its anglar acceleration is -2.8rad/s2, what is the angula

snow_lady [41]

Here we know that

$\omega_i = - 8.4 rad/s$

$\alpha = - 2.8 rad/s^2$

$t = 1.5 s$

now from kinematics we have

$\omega_f = \omega_i + \alpha t$

now from above all values we have

$\omega_f = (-8.4 rad/s) + (-2.8 rad/s^2)(1.5)$

$\omega_f = -8.4 + (-4.2)$

$\omega_f = -12.6 rad/s$

so final angular speed is -12.6 rad/s

6 0

3 years ago

What s physics?

Alex777 [14]

The answer is (B. The study of Matter and Energy) but technically you could consider physics all of these as engineering is based on physics and that would be the study of inventions, chemistry and biology were both discovered because of physics, and physics invokes more math than any other subject as it applies math to the entire Universe.

7 0

4 years ago

Read 2 more answers