Answer:
B. False
Explanation:
Without good technique and posture you can end up getting injured.
. A ventilation fan has blades 0.25 m long rotating at 20 rpm (revolutions per minute). What is the centripetal acceleration of a point on the outer tip of a blade
Answer:
The centripetal acceleration of a point on the outer tip of a blade is 1.097 m/s²
Explanation:
Given;
length of the fan blade, r = 0.25 m
angular speed = 20 rpm
The angular speed in rad/s is given as;
[tex]\omega = \frac{20 \ rev}{ \ \ \min} \ \times \ \frac{2\pi}{1 \ rev} \ \times \ \frac{1 \ \min}{60s} = 2.095 \ rad/s \\\\[/tex]
The centripetal acceleration of a point on the outer tip of a blade is given as;
[tex]\alpha_c = \frac{v^2}{r} = \omega ^2r[/tex]
[tex]\alpha _c = (2.095)^2(0.25)\\\\\alpha _c =1.097 \ m/s^2[/tex]
Therefore, the centripetal acceleration of a point on the outer tip of a blade is 1.097 m/s²
Answer:
The centripetal acceleration = [tex]1.1m/s^2[/tex]Explanation:
Given
[tex]rpm = 20[/tex]
therefore,
[tex]20rpm = \frac{20*2\pi}{60}\\\\=2.1 rad/s = w[/tex]
From,
[tex]V = rw\\\\V = 0.25 * 2.1\\\\V = 0.525m/s[/tex]
Centripetal acceleration,
[tex]a_c = \frac{V^2}{r}\\\\a_c = \frac{0.525^2}{0.25}\\\\a_c = 1.1m/s^2[/tex]
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Prior Knowledge
1. What do a light bulb, a toaster, a radio, and a computer all have in common?
Answer:
They all have electrical currents
Answer:
They have electronic parts and currents
the amplitude of an oscillator decreases to 36.8% of its initial value in 10.0 s. what is the value of the time constant
Answer:
τ = 5 s
Explanation:
When a vibrating body is damped. Its amplitude starts to decrease. This decrement is exponential. And it is given as follows:
[tex]X = X_{0}e^{-\frac{t}{2\tau}[/tex]
where,
τ = Time Constant = ?
X = Instantaneous value of amplitude
X₀ = Initial Value of amplitude
t = time interval = 10 s
The ratio of decrement is given as:
[tex]\frac{X}{X_0} = 36.8\% = 0.368[/tex]
therefore, using these values, we get:
[tex]\frac{X}{X_{0}} = 0.368 = e^{\frac{10\ s}{2\tau}}[/tex]
Taking natural log (ln) on both sides, we get:
[tex]ln(0.368) = \frac{10\ s}{2\tau}\\\\\tau = \frac{10\ s}{2ln(0.368)}[/tex]
τ = 5 s
The value of the time constant for the decrease in the amplitude of this oscillator is 5.
Given the following data:
Decrease in amplitude = 36.8% = 0.368Time = 10.0 seconds.To determine the value of the time constant:
Mathematically, the amplitude for damped harmonic motion is given by the formula:
[tex]X = X_o e^\frac{t}{2 \tau}[/tex]
Where:
t is the time.[tex]\tau[/tex] is the time constant.X is the instantaneous value of amplitude.[tex]X_o[/tex] is the initial value of amplitude.Rearranging the formula, we have:
[tex]\frac{X}{X_o} = e^{-\frac{t}{2 \tau}}[/tex]
Substituting the given parameters into the formula, we have;
[tex]0.368 = e^\frac{-10}{2 \tau}\\\\ln(0.368) = \frac{-10}{2 \tau}\\\\-0.9997 = \frac{-10}{2 \tau}\\\\2 \tau \times -0.9997 = 10\\\\-1.9994\tau=-10\\\\\tau =\frac{-10}{-1.9994} \\\\\tau = 5.0[/tex]
Time constant = 5
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The static frictional force between a 95-kilogram object and the floor is 45 Newtons. The kinetic frictional force is only 22 Newtons. What force must be exerted to accelerate the box at 0.5 meters per second to the south?
Answer:
F = 69.5 [N]
Explanation:
We must remember that the friction force is defined as the product of the normal force by the coefficient of friction, and it can be calculated by the following expression.
[tex]f=N*miu[/tex]
where:
N = normal force [N]
miu = friction coefficient
f = friction force = 22 [N]
Now we must calculate the force exerted by means of Newton's second law which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
[tex]F - f = m*a[/tex]
where:
F = force exerted [N]
f = friction force [N]
m = mass = 95 [kg]
a = acceleration = 0.5 [m/s²]
Now replacing:
[tex]F - 22 = 95*0.5\\F = 47.5 + 22\\F = 69.5 [N][/tex]
A 420N force act on a 400N object, and the force is from the north.
In what direction will the object move?
Forward
Backboard
North
South
Answer:
I believe its forward or south :D
Explanation:
An object in static equilibrium has a coefficient of static friction as 0.110. If the normal force acting on the object is 95.0 newtons, what is the mass of the object? A. 9.70 kilograms B. 10.5 kilograms C. 85.3 kilograms D. 95.0 kilograms E. 1.00 × 102 kilograms
Answer:
9.70 kilograms
Explanation:
I got a 100% on my test
The mass of the object is 9.7 kg. Option (A) is correct.
What is normal force?Every day, we experience the normal force. For instance, when a book is placed on a table, the usual response force prevents the book from falling through the table, even though gravity is pulling the book downward. That implies that there is a force acting to push it upward. The word "normal force" refers to the force. Normal in this context refers to being perpendicular to the ground.
Given parameters:
the normal force acting on the object is: N = 95.0 newtons.
coefficient of static friction: μ = 0.110.
We have to find mass of the object: m = ?
We know that:
Normal force = weight of the object
⇒ N = mg
⇒ m = N/g = 95.0/9.8 kg = 9.7 kg
Hence, the mass of the object be 9.7 kg.
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Dominic has a brain injury. Why is this MOST likely to be a serious injury?
If Dominic has a brain injury, then he must have sustained a serious injury.
Functions of the brainThe brain coordinates all the activities in the body such as speech, locomotion, coordination and intelligence. This makes the brain the master point of control in the body.
Brain injuryWhenever there is an injury to the brain, various parts of the body could be affected. Functions such as speech, locomotion and general coordination may become largely impaired.
Therefore, if Dominic has a brain injury, then he must have sustained a serious injury.
Learn more about the brain: https://brainly.com/question/5361122
A graph titled Position versus time for with horizontal axis time (seconds) and vertical axis position (meters). A straight blue line runs with an upward slope from 0 seconds 3 meters to 4 seconds 15 meters.
The starting position of this object is
[___] m.
The object is traveling at a velocity of
[___] m/s.
Answer:
The starting position of this object is
3m.
The object is traveling at a velocity of
3m/s.
Answer:
it never moved (c or 3)
Explanation:
np
A visitor is staying in a tent that is 11 kilometers west of the closest point on a shoreline to a coral reef. The coral reef is 3 kilometers due south of the shoreline. The visitor plans to travel from the tent to the coral reef by running and swimming. If the visitor runs at a rate of 7 kmph and swims at a rate of 2 kmph, how far should the visitor run to minimize the time it takes to reach the coral reef
Answer:
Explanation:
From the question, it says that their tent is 11 km away from the shore which is also 3 km away from the coral reef. Essentially, the tent us 11 + 3 km away from the coral reef, and that's 14 km. He has to run at a rate of 7 know to cover an 11 km length and swim at 2 kmph to cover a 3 km length.
All the visitor needs to do is run more than 7 kmph to reduce the days time. For example, running at 11 kmph takes him or her exactly 1 hour to reach the shore, before taking another swim of about an hour to reach the reef
Answer:
10.11
Explanation:
?
What is the definition of Phyical changes
Answer:
A physical change is the change to the physical properties of an object.
Explanation:
As an example if I take a piece of paper and cut it in half that would be a physical change. Water freezing into ice is also a physical change.