Answer:
c
Explanation:
changes from a liquid to a solid
The peripheral speed of the tooth of a 10-in.-diameter circular saw blade is 230 ft/s when the power to the saw is turned off. The speed of the tooth decreases at a constant rate, and the blade comes to rest in 17 s. Determine the time at which the total acceleration of the tooth is 130 ft/s2.
Answer:
The time is [tex]t_r =21.58 \ s[/tex]
Explanation:
From the question we are told that
The diameter of the circular saw is [tex]d = 10 \ in = \frac{10}{12} = 0.833 \ feet[/tex]
The peripheral speed is [tex]u = 230 \ ft/s[/tex]
The time taken for the blade to come to rest is t = 17 s
The total acceleration of the tooth considered is [tex]a = 130 \ ft/s^2[/tex]
Generally the radius of the blade is mathematically represented as
[tex]r = \frac{0.833}{2}= 0. 4165 \ feet[/tex]
Generally the tangential acceleration of the blade is mathematically represented as
[tex]a__{t}} = \frac{v - u}{t}[/tex]
Here v is the final velocity of the tooth of the blade which is zero since the blade came to rest
so
[tex]a__{t}} = \frac{0 - 230}{ 17}[/tex]
=> [tex]a__{t}} = - 13.53 \ ft/s^2[/tex]
Generally the total acceleration of the tooth of the blade is mathematically represented as
[tex]a = \sqrt{a_t^2 + a_r^2}[/tex]
Here [tex]a_r[/tex] is the radial acceleration , now making [tex]a_r[/tex] the subject of the formula we have that
[tex]130= \sqrt{13.56 ^2 + a_r^2}[/tex]
=> [tex]a_r = \sqrt{130^2 -(- 13.56)^2}[/tex]
=> [tex]a_r = 129.3 \ m/s^2[/tex]
Generally radial acceleration is mathematically represented as
[tex]a_r = \frac{v_r^2}{r}[/tex]
Here [tex]v_r[/tex] is the velocity at which the total acceleration is 130 ft/s2.
=> [tex]v_r = \sqrt{a_r * r }[/tex]
=> [tex]v_r = \sqrt{129.3 * 0.4165 }[/tex]
=> [tex]v_r = 7.34 \ m/s[/tex]
Generally the time at which the total acceleration is 130 ft/s2. is mathematically represented as
[tex]t_r = \frac{7.34 - 300}{a_t}[/tex]
=> [tex]t_r = \frac{7.34 - 300}{-13.56}[/tex]
=> [tex]t_r =21.58 \ s[/tex]
How long will it take a 2190 W motor to lift a 1.47 x 104 g box, 6.34 x 104 mm vertically.
Answer:
4.2s
Explanation:
Given parameters:
Power = 2190W
Mass of box = 1.47 x 10⁴g
distance = 6.34 x 10⁴mm
Unknown:
Time = ?
Solution:
Power is the rate at which work is done;
Mathematically;
Power = [tex]\frac{work done}{time}[/tex]
Time = [tex]\frac{work done}{power}[/tex]
Work done = weight x height
convert mass to kg;
100g = 1kg;
1.47 x 10⁴g = 14.7kg
convert the height to m;
1000mm = 1m
6.34 x 10⁴mm gives 63.4m
Work done = 14.7 x 9.8 x 63.4 = 9133.4J
Time taken = [tex]\frac{9133.4}{2190}[/tex] = 4.2s
The force of gravity acting on you will increase if you
A. burrow deep inside the planet.
B. stand on a planet with a radius that is shrinking
C. both of these
D.none of these
Answer:
C.
Explanation:
the closer you get to the centre of an object the greater its gravitational pull- A is correct
If the radius increases the gravity decreases and rise versa - B is correct
the answer is C
The force of gravity acting on you will increase if you stand on a planet with a radius that is shrinking. So, option (B) is orrect.
What is force?
Force is an external agent that has the power to alter a body's resting or moving condition. It has a size and a movement. The direction of the force is referred to as the force's direction, and the application of force is the place at which the force is applied.
The force of gravity acting on an object due to a planet is given by: F = GMm/R².
Where, G is universal gravitational constant . M and m is masses of the planet and the object respectively and R is distance between them.
Hence, when you stand on a planet with a radius that is shrinking; distance between you and planet decreases. So, the force of gravity acting on you will increase. So, option (B) is correct.
But in the case of burrow deep inside the planet: gravitational force due to outer shell becomes zero. So, effective gravitational force decreases.
Learn more about force here:
https://brainly.com/question/13191643
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How long would it take a 500. W electric motor to do 15010 J of work?
Ken Griffey, Jr's warehouse shot in the 1933 home run derby travelled 93 feet per second for 5 seconds. How far did he hit the ball?
Answer:
465 feet because 93*5 = 465, btw that was 1993 not 1933
Explanation:
a 2000 kg car moving down the road runs into a 5000 kg stationary suv. The car applies a force of 1400 n on the suv what is the magnitude of force applied by the suv on the car
Answer:
F_suv= 49050 N
Explanation:
We are told that a 2000 kg car moving down the road runs into a 5000 kg stationary suv. The car applies a force of 1400 N on the suv.
Now, according Newton's first law of motion, an object will continue in it's present state of rest except it is acted upon by an external body.
This means the force acting on the stationary Suv is force of gravity.
Thus; F_suv = 5000 × 9.81
F_suv= 49050 N
for a solar eclipse to occur which of the following alignments must be necessary
If a car traveled 50 meters in 2 seconds, what will the velocity be? (Write the answer with a number, on decimal if needed, then a space and the units, for example 5.7 m/s)
Answer:
The answer is 25 m/sExplanation:
The velocity of the car can be found by using the formula
[tex]v = \frac{d}{t} \\ [/tex]
d is the distance
t is the time taken
From the question we have
[tex]v = \frac{50}{2} \\ [/tex]
We have the final answer as
25 m/sHope this helps you
Sean and Tommy are debating the positive and negative impacts of technology on environmental quality. Tommy is listing the negative impacts. Which of the following would help his argument? (2 points)
Grupp av svarsalternativ
Solar panels have become more effective due to technological improvements.
Technology has helped make recycling to be more efficient.
It has created new ways to clean up oil spills.
Factories contribute to air and water pollution.
Answer:
Factories contribute to air and water pollution.
Explanation:
How do covalentes bonds form
True or False. A compound is formed when two or more elements are combined to make a
new substance with its own properties.
Anyone?
Answer:
I believe It's true. Since from memory I KNOW a compound is formed when elements are combined chemically.
Answer: correct
Explanation: a compound is 2 or more elements formed to make a completely new thing. For example, water is a compound. Why? Well, water is h20. What is h20? It’s Hydrogen and Oxygen. Oxygen is also a compound. Another example is CO2 (carbon dioxide) it’s made of carbon and oxygen, so it’s a compound! A element is just a pure substance. It’s not made up of other materials. It’s in its purest form.
The picture below shows a science model made with a balloon, cord, and radiosonde.
Image showing a science model made with a balloon; at the bottom of the balloon is a cord with a radiosonde attached to it.
Which of these is most likely the function of the science model?
To change the density of air
To increase the humidity in air
To reduce the atmospheric pressure
To predict extreme weather conditions
Answer:
Since the person above didn't answer correctly I will, the correct option is (D) this is because the picture shown is of a weather balloon and the purpose of this device is to predict weather and its conditions
Hope this helped! (: Have a nice day
Answer: To predict extreme weather conditions
A radiosonde is a small tool that is put under a balloon filled with either hydrogen or helium. As the radiosonde goes up it measures pressure, temperature, and relative humidity.
A 60-kg woman runs up a staircase 15 m high (vertically) in 20 s.
Required:
a. How much power does she expend?
b. What is her horsepowerrating.
Answer:
(a) 441 W (b) 0.59 hP
Explanation:
Given that,
Mass of a woman, m = 60 kg
Height of a staircase, h = 15 m
Time, t = 20 s
(a) We need to find the power she expend. Work done per unit time is called power. It is given by :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{mgh}{t}\\\\P=\dfrac{60\times 9.8\times 15}{20}\\\\P=441\ W[/tex]
( b) Since, 1 hP = 745.7 W
P = 0.59 hP
Which of the following is made up of vibrating electric and magnetic fields
traveling together?
A. An electromagnetic wave
B. A generator
C. An induced current
D. An electromagnet
Answer:
A. An electromagnetic wave
Explanation:
A P E X
How does temperature effect density and the flow of convection currents?
Answer:
Convection
Explanation:
Convection is heat transfer due to a density differential within a fluid. As water's temperature increases in the presence of a heat source, it will become less dense and rise. As it moves up and away from the heat source, it cools and becomes more dense and sinks.
A hockey puck is sliding on frictionless ice, in an Eastward direction. It collides with a second hockey puck, initially stationary, which then goes off in the Northern direction. What direction is the first hockey puck moving after the collision
Answer:
Southeast
Explanation:
We have to put into cognisance that the first hockey puck is moving in the eastern direction in the first instance, before it hits the other stationary hockey puck. And as such, on hitting the second puck, it's displacement is expected to differ, as a result of the collision. While the stationary puck will the move in the Eastern direction, it changes the direction of the first puck, from eastern to southeastern
If a star appears to wobble back back and forth, or its light seems to change in brightness, what might be the cause?
Answer:
The first method, known as the wobble method, looks for changes in a star's relative velocity caused by the gravitational tug of a nearby planet. ... If a planet's orbit crosses between its parent star and Earth, it will block some of the light and cause the star to dim.
Explanation:
We all know that the chains of gravity shackle a planet to its star. That star's enormous gravitational influence keeps its planetary family in orbit. But gravity works both ways: as the planets sweep around in their orbits, they tug on their parent stars to and fro, causing those stars to wobble
Answer:
The way it’s orbiting
Explanation:
Explain the procedures used and data recorded to identify a crystalline mineral based on its properties.
Answer:
By examining its external shape, color, hardness, etc.
Explanation:
The first group of planets that are made of rock and closest to the sun
Answer:
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun
what is a factor that scientists use to classify orders of soil?
After school, a student rides his bike back home. The student lives 750 meters from the school. If it takes the student 3 minutes to get home, what is his average speed?
Answer:
(4,5) and (8,10) what is the slope
Explanation:
After school, a student rides his bike back home. The student lives 750 meters from the school. If it takes the student 3 minutes to get home, what is his average speed?
Explain how you would determine how much air there is between a vector addition in the displacement of the actual trip taken. Why aren’t vectors true straight-line paths in the real world? Would you expect a vector addition to be larger or smaller than the actual trip taken? Why?
Answer:
This is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. This enables more atoms in the metal to become aligned hence becoming more magnetized.
or...
A method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
Hope this helps☺️
if an object is moving with a velocity of 25m/s, an acceleration of 5m/s and has a travel time of 5s, what is the final velocity of the object?
V = at + V0
where v0 is the initial speed, a is the acceleration and t is the time.
So:
v = 5m/s^2*5s + 25m/s = 50 m/s
A baseball is thrown at an angle of 25 degrees relative to the ground at a speed of 23 m/s. If the ball was caught 42 m from the thrower:
What is the initial vertical velocity?
What is the initial horizontal velocity?
How long was it in the air?
How high did the ball travel before being caught?
Answer:
a) [tex] v_{0y} = 9.72 m/s [/tex]
b) [tex] v_{0x} = 20.85 m/s [/tex]
c) [tex] t = 2.01 s [/tex]
d) [tex] h_{max} = 4.82 m [/tex]
Explanation:
a) The initial vertical velocity is given by:
[tex] v_{0y} = v*sin(\theta) [/tex]
Where:
θ: 25°
v: is the magnitude of the speed = 23 m/s
[tex] v_{0y} = 23 m/s*sin(25) = 9.72 m/s [/tex]
b) The initial horizontal velocity can be calculated as follows:
[tex] v_{0x} = v*cos(\theta) = 23 m/s*cos(25) = 20.85 m/s [/tex]
c) The flight time can be calculated using the following equation:
[tex] v_{0x} = \frac{x}{t} [/tex]
Where:
x: is the total distance = 42 m
[tex] t = \frac{x}{v_{0x}} = \frac{42 m}{20.85 m/s} = 2.01 s [/tex]
d) The maximum height is given by:
[tex] v_{fy}^{2} = v_{0y}^{2} - 2gh_{max} [/tex]
Where:
[tex] v_{fy}[/tex]: is the final vertical velocity =0 (at the maximum heigth)
g: is the gravity = 9.81 m/s²
[tex]h_{max} = \frac{v_{0y}^{2}}{2g} = \frac{(9.72 m/s)^{2}}{2*9.81 m/s^{2}} = 4.82 m[/tex]
I hope it helps you!
When the wooden block is placed in the water and allowed to float to the top, what percentage of it is submerged
Answer:
This question is incomplete
Explanation:
This question is incomplete. However, what is described in the question is known as upthrust. Upthrust is an upward force on an object (in this case the wooden block) provided by the liquid (water) as a result of it displacing some of the liquid. Thus floating objects will normally displace some part of the liquid; making some part of it to be submerged in water.
The percentage of the submerged wooden block can be calculated as
length (in height) of the wood block submerged in water/total length (in height) of the wood × 100
Two masses are to collide directly with each other. One has a mass of 5 kg and a velocity of 2 m/s. The other has a mass of 3 kg and a velocity of 1 m/2. The collision is perfectly inelastic. Find the velocity of the masses after the collision.
Answer:
v₃ = 1.625 [m/s]
Explanation:
To solve this problem we must use the definition of linear momentum conservation, which tells us that momentum is conserved before and after a collision.
Since the collision is inelastic, the two bodies are joined after the collision.
P = m*v [kg*m/s]
m = mass [kg]
v = velocity [m/s]
where:
P = lineal momentum [kg*m/s]
Now, it is important to clarify that in the following equation we will take the left side of the equation as the momentum before the collision and the right side of the equal sign as the momentum after the collision.
Pbefore = Pafter
(m₁*v₁) + (m₂*v₂) = (m₁+m₂)*v₃
where:
m₁ = mass one = 5 [kg]
v₁ = velocity of the mass one = 2 [m/s]
m₂ = mass two = 3 [kg]
v₂ = velocity of the mass two = 1 [m/s]
v₃ = velocity of the combined masses after the collision [m/s]
Now replacing we have:
(5*2) + (3*1) = (5 + 3)*v₃
10 + 3 = 8*v₃
v₃ = 13/8
v₃ = 1.625 [m/s]
A coiled telephone cord forms a spiral with 65.0 turns, a diameter of 1.30 cm, and an unstretched length of 65.5 cm. Determine the inductance of one conductor in the unstretched cord.
Answer:
[tex]L=1.07\ \mu H[/tex]
Explanation:
Given that,
No of turns in a coiled telephone cord is 65
The diameter of the coil, d = 1.3 cm = 0.013 m
Radius, r = 0.0065 m
Unstretched length of the coil, l = 65.5 cm = 0.655 m
We need to find the inductance of one conductor in the unstretched cord. The formula for the inductance is given by :
[tex]L=\dfrac{\mu_oN^2 A}{l}\\\\L=\dfrac{4\pi \times 10^{-7}\times (65)^2\times \pi (0.0065)^2}{0.655 }\\\\L=1.07\times 10^{-6}\ H\\\\L=1.07\ \mu H[/tex]
So, the inductance of one conductor in the unstretched cord is [tex]1.07\ \mu H[/tex].
1000 kg car takes travels on a circular track having radius 100 m with speed 10 m/s. What is the minimum coefficient of static friction between tires and track needed to keep the car on circular path. *
A- 0.01
B- 0.05
C- 0.1
D- 0.2
Answer:
C. 0.1
Explanation:
Regular exercise can:
A.
Reduce stress and anxiety
B.
Boost your immune system
C.
Increase your overall feeling of wellness
D.
All of the above
Answer:
D
Explanation:
yes or no
1.the ink of a pen that is used for writing is not a colloid
2.the blood consists of solid particles and plasma are considered a kind of colloid.
Answer:
1. No, it is a colloid
2. Yes
Explanation: