Answer:
Explanation:
Due to change in the position of 3 kg mass , the moment of inertia of the system changes , due to which angular speed changes . We shall apply conservation of angular momentum , because no external torque is acting .
Initial moment of inertia I₁ = M R² = 3 x 1 ² = 3 kg m²
Final moment of inertia I₂ = M R² = 3 x .3 ² = 0.27 kg m²
Applying law of conservation of angular momentum
I₁ ω₁ = I₂ ω₂
Putting the values ,
3 x .75 = .27 x ω₂
ω₂ = 8.33 rad / s
New angular speed = 8.33 rad /s .
One reason why it’s often easy to miss an action-reaction pair is because of the ________ of one of the objects.
Answer:
an action-reaction pair is because one of the objects is often much more massive and appears to remain motionless when a force acts on it. It has so much inertia, or tendency to remain at rest, that it hardly
A car is sitting still. It accelerates to a constant speed then it decelerates again to zero speed. While the car is accelerating how do the directions of the angular acceleration and angular velocity of one of the wheels compare
Answer:
in the acceleration process the quantity α and w must increase
the deceleration process the alpha quantity must constant a direction opposite to the angular velocity
Explanation:
Acceleration and angular velocity are related to linear
v = w xr
a = αx r
The bold letters indicate vectors and the cross is a vector product, therefore if
we can see that the relationship between linear and angular variables is direct
therefore in the acceleration process the quantity α and w must increase as well as their linear counterparts
in the deceleration process the alpha quantity must constant as the linear acceleration and must have a direction opposite to the angular velocity
A simple pendulum of length 5.5 m makes 10.0 complete swings in 25 s what is the acceleration due to gravity at the location of the pendulum ?
Answer:
The acceleration due to gravity at the location of the pendulum is 34.74 m/s².
Explanation:
Given that,
The length of a simple pendulum, l = 5.5 m
It makes 10.0 complete swings in 25 s.
Frequency of pendulum,
[tex]f=\dfrac{10}{25}\\\\f=0.4\ Hz[/tex]
The time period of a simple pendulum is given by :
[tex]T=2\pi \sqrt{\dfrac{l}{g}}[/tex]
Frequency,
[tex]f=\dfrac{1}{T}\\\\f=\dfrac{1}{2\pi \sqrt{\dfrac{l}{g}} }\\\\f=\dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}}[/tex]
g is the acceleration due to gravity at the location where the pendulum is placed. So,
[tex]f^2=\dfrac{g}{4\pi^2l}\\\\g=f^2\times 4\pi^2l\\\\g=0.4^2\times 4\pi^2\times 5.5\\\\g=34.74\ m/s^2[/tex]
So, the acceleration due to gravity at the location of the pendulum is 34.74 m/s².
1.A river flowing steadily at a rate of 240 m3/s is considered for hydroelectric power generation. It is determined that a dam can be built to collect water and release it from an elevation difference of 50 m to generate power. Determine how much power can be generated from this river water after the dam is filled
Answer:
the power that can be generated by the river is 117.6 MW
Explanation:
Given that;
Volume flow rate of river v = 240 m³/s
Height above the lake surface a h = 50 m
Amount of power can be generated from this river water after the dam is filled = ?
Now the collected water in the dam contains potential energy which is used for the power generation,
hence, total mechanical energy is due to potential energy alone.
[tex]E_{mech}[/tex] = m(gh)
first we determine the mass flow rate of the fluid m
m = p×v
where p is density ( 1000 kg/m³
so we substitute
m = 1000kg/m³ × 240 m³/s
m = 240000 kg/s
so we plug in our values into ( [tex]E_{mech}[/tex] = m(gh) kJ/kg )
[tex]E_{mech}[/tex] = 240000 × 9.8 × 50
[tex]E_{mech}[/tex] = 117600000 W
[tex]E_{mech}[/tex] = 117.6 MW
Therefore, the power that can be generated by the river is 117.6 MW
Fred's lightbulb is 45% efficient, and Fran's is 75% efficient. If they both use the same amount of electric energy, which produces more light energy?
Answer:
Frank's 75% efficient light bulb will shine brighter.
Explanation:
The brightness of a bulb is gotten from the power equation;
P = I²R
The more the power rating in watts, the more the brightness.
Now, if they both use the same amount of energy but yet have different efficiency, it means we will just multiply the efficiency by the power.
Thus, 75% efficiency will yield more power than a 45% efficient one.
Therefore, Frank's light bulb will shine brighter.
According to Coulomb's Law, if the distance between two charged particles is doubled, the electric force will be _________. *
Answer: reduced by 1/4
Explanation:
The force will be reduced by 1/4. Try plugging in 2r, then squaring it. You will get 4r^2, which is essentially dividing the force by 4
A taxi hurries with a constant speed of 60 miles per hour. How long will it take to travel a distance of 130 miles
Answer:
2.17 hrs
Explanation:
time = distance / velocity
We know that distance = 130 miles and velocity = 60 miles/h.
t = d / v
t = 130 miles / 60 miles/h
t = 2.17 hrs
It takes about 2.17 hours to travel a distance of 130 miles. Hope this helps, thank you !!
A river flows with a uniform velocity vr. A person in a motorboat travels 1.22 km upstream, at which time she passes a log floating by. Always with the same engine throttle setting, the boater continues to travel upstream for another 1.45 km, which takes her 69.1 min. She then turns the boat around and returns downstream to her starting point, which she reaches at the same time as the same log does. How much time does the boater spend traveling back downstream
Answer:
t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex], v_r = 1 m/s t ’= 547.19 s
Explanation:
This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.
By the time the boat goes up the river
v_b - v_r = d / t
By the time the boat goes down the river
v_b + v_r = d '/ t'
let's subtract the equations
2 v_r = d ’/ t’ - d / t
d ’/ t’ = 2v_r + d / t
[tex]t' = \frac{d'}{ \frac{d}{t}+ 2 v_r }[/tex]
In the exercise they tell us
d = 1.22 +1.45 = 2.67 km= 2.67 10³ m
d ’= 1.45 km= 1.45 1.³ m
at time t = 69.1 min (60 s / 1min) = 4146 s
the speed of river is v_r
t ’= [tex]\frac{1.45 \ 10^3}{ \frac{ 2670}{4146} \ + 2 \ v_r}[/tex]
t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex]
In order to complete the calculation, we must assume a river speed
v_r = 1 m / s
let's calculate
t ’= [tex]\frac{ 1450}{ 0.6499 + 2 \ 1}[/tex]
t ’= 547.19 s
A 72-kg man stands on a spring scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.2 m/s in 0.80 s. The elevator travels with this constant speed for 5.0 s, undergoes a uniform negative acceleration for 1.5 s, and then comes to rest. What does the spring scale register During the first 0.80s of the elevator’s ascent?
Answer:
Explanation:
During the first .8 s , the elevator is under acceleration . It starts from initial velocity u = 0 , final velocity v = 1.2 m /s , time = .8 s
v = u + at
1.2 = 0 + .8 a
a = 1.2 / .8
= 1.5 m /s²
During the acceleration in upward direction , let reaction force of ground on man be R .
Net force on man = R - mg
Applying Newton's 2 nd law
R - mg = ma
R = m ( g + a )
= 72 ( 9.8 + 1.5 )
= 813.6 N .
This reaction force will be measured by spring scale , so reading of spring scale will be 813.6 N .
Newtons third law is called law of action and reaction?
Answer:
His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. ... In reaction, a thrusting force is produced in the opposite direction.
Explanation:
Answer:
These two forces are called action and reaction forces and are the subject of Newton's third law of motion Formally stated Newton's third law is For every action
Explanation:
You have been handed an unknown battery. Using your multimeter, you determine that when a 4.30 resistor is connected across the battery's terminals, the current in the battery is 0.500 A. When this resistor is replaced by an 9.4 resistor, the current drops to 0.250 A. From those data, find the emf and internal resistance of your battery.
Answer:
Ri = 0.8 Ω
V= 2.55 V
Explanation:
Since the internal resistance of the battery is connected in series with the resistor connected across the battery's terminals, applying Ohm's Law, we can write the following equation, when R₁=4.30 Ω, and I₁=0.500A:[tex]I_{1} = \frac{V}{R_{i} + 4.3 \Omega } = 0.500 A (1)[/tex]
We can apply exactly this same expression, when R₂ = 9.4Ω, and I₂ = 0.250A:[tex]I_{2} = \frac{V}{R_{i} + 9.4 \Omega} } = 0.250 A (2)[/tex]
Now, we can divide (1) by (2) as follows:[tex]\frac{R_{i} + 9.4 \Omega}{R_{i} + 4.3 \Omega} = \frac{I_{1} }{I_{2}} = 2 (3)[/tex]
Solving for Ri, we get Ri = 0.8 ΩReplacing this value in (1) we can solve for V, as follows:V = I₁ * (Ri + R₁) = 0.500 A * (0.8Ω + 4.3Ω) = 2.55 V⇒ V = 2.55 V (emf of the battery)
You want to see how your new belt buckle matches your new hat. Your eyes are 114 mm below the top of the hat and 800 mm above the buckle. You walk up to your mirror and notice that the mirror is exactly large enough and exactly in the right position for you see both the top of the hat and the buckle.
1. What is the position of the top edge of the mirror relative to your eyes?2. How tall is the mirror?
Answer:
[tex]x=0.057m[/tex]
[tex]h=0.457m[/tex]
Explanation:
From the question we are told that
Distance of eyes from the top of hat [tex]d_1=114mm[/tex]
Distance of eyes from buckle [tex]d_2=800mm[/tex]
Generally position of mirror relative eyes x is mathematically given as
[tex]x=\frac{114}{2}[/tex]
[tex]x=57mm[/tex]
[tex]x=0.057m[/tex]
Generally the height of the mirror h is mathematically given as
[tex]h=\frac{(Buckle\ below\ the\ hat)+(Buckle\ below\ the\ hat)}{2}[/tex]
[tex]h=\frac{(114)+(800)}{2}[/tex]
[tex]h=457mm[/tex]
[tex]h=0.457m[/tex]
define stress engineering science
Answer:
Stress, in physical sciences and engineering, force per unit area within materials that arises from externally applied forces, uneven heating, or permanent deformation and that permits an accurate description and prediction of elastic, plastic, and fluid behaviour.
I hope it's helpful!
A student weighing 5.4 × 102 newtons takes 15 seconds to run up a hill. The top of the hill is 10 meters vertically above her starting point. What power does the student develop during her run?
Answer:
P = 360 Watts
Explanation:
Given that,
The weight of a student, [tex]F=5.4\times 10^2\ N[/tex]
It takes 15 seconds to run up a hill.
The top of the hill is 10 meters vertically above her starting point.
We need to find the power develop during her run. We know that te power developed is given by :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{mgh}{t}\\\\P=\dfrac{5.4\times 10^2\times 10}{15}\\\\P=360\ W[/tex]
So, the power develop during her run is 360 W.
A bottle of water at a room temperature of 21.0 C is placed into a refrigerator
with an air temperature of 4.5C. The thermal energy will move — *
A. from the cooler air to lower the temperature of the water to 4.5 C
B. in both directions until the temperature is equal in the water and the air
C. from the water to the air until the water temperature is zero degrees Celsius
O D. from the water to the air until the temperature is equal in both
Answer:
B. in both directions until the temperature is equal in the water and the air
Explanation:
When a warm body is in contact with a cool body , there is exchange of heat energy in both sides until there is attainment of equilibrium temperature . At this temperature both the body attains equal temperature . Initially rate of heat radiated by warm body is more than that from cool body , but after attainment of equilibrium , the rate becomes equal to each other . This is called dynamic equilibrium .
Hence option B is correct .
A police officer is parked by the side of the road, when a speeding car travelling at 50 mi/hrpasses. The police car immediately pursues it, accelerating at a rate of 10 mi/hr per second.The road is fairly busy, so the officer will not go faster than a top speed of 70 mi/hr. How longwill it take before the officer catches up to the speeding car, and how far will it have travelled inorder to do so
Answer:
a) time taken to catch up with speeding car is 12.25 secs
b) the police car will travel 273.8 m to catch up with the speeding car
Explanation:
Given that;
speed of car [tex]V_{c}[/tex] = 50 mi/hr = 22.352 m/s
acceleration of police car = 10 mi/hr = 4.47 m/s²
[tex]V_{f}[/tex] = 70 mi/hr = 31.29 m/s
Now time taken to reach maximum speed is t₁
so
[tex]V_{f}[/tex] = [tex]V_{i}[/tex] + at₁
we substitute
31.29 = 0 + 4.47t₁
t₁ = 31.29 / 4.47
t₁ = 7 sec
now
d₁ = 0 + 1/2 × at₁²
d₁ = 0 + 1/2 × 0 + 4.47×(7)²
d₁ = 109.5 m
so distance travelled by the speeding car in time t₁ will be
[tex]d_{c}[/tex] = [tex]V_{c}[/tex] × t₁
we substitute
[tex]d_{c}[/tex] = 22.352 × 7
[tex]d_{c}[/tex] = 156.46 m
now distance between polive car and speeding car
Δd = [tex]d_{c}[/tex] - d₁
Δd = 156.46 - 109.5
Δd = 46.96 m
time taken to cover Δd will be
t₂ = Δd / ( [tex]V_{f}[/tex] - [tex]V_{c}[/tex] )
t₂ = 46.96 / ( 31.29 - 22.352 )
t₂ = 46.96 / 8.938
t₂ = 5.25 sec
distance travelled by the police in time t₂ will be
d₂ = [tex]V_{f}[/tex] × t₂
d₂ = 31.29 × 5.25
d₂ = 164.3 m
a) How long will it take before the officer catches up to the speeding car;
time taken to catch up with speeding car;
t = t₁ + t₂
t = 7 + 5.25
t = 12.25 secs
Therefore, time taken to catch up with speeding car is 12.25 secs
b) how far will it have travelled in order to do so;
distance = d₁ + d₂
distance = 109.5 + 164.3
distance = 273.8 m
Therefore, the police car will travel 273.8 m to catch up with the speeding car
Which object exerts the action force?
Which object exerts the reaction force?
In what direction does the action force push?
In what direction does the reaction force push?
For answering this question,let us assume that a person is pushing against the walls,so now:
Which object exerts the action force?
PersonWhich object exerts the reaction force?
WallIn what direction does the action force push?
BackwardIn what direction does the reaction force push?
ForwardThe answer varies from different scenarios.
Answer:
diver, diving board, down, and up.
Explanation:
A friend comments to you that there was a beautiful, thin sliver of a Moon visible in the early morning just before sunrise. Which phase of the Moon would this be, and in what direction would you look to see the Moon (in the southern sky, on the eastern horizon, on the western horizon, high in the sky, etc.)?
Answer: Waning Crescent
Explanation:
A Chinook salmon can jump out of water with a speed of 7.20 m/s . How far horizontally can a Chinook salmon travel through the air if it leaves the water with an initial angle of =29.0° with respect to the horizontal? (Neglect any effects due to air resistance.)
d=
Explanation:
The vertical component of the salmon's velocity is 7.2 m/s x sin 29 = 3.49 m/s
If g = 9.81 m/s^2, the salmon takes
(3.49 m/s) / (9.81 m/s^2) = 0.356 s to reach the highest point of its trajectory.
It takes another 0.356 s to fall back into the water again.
So the salmon is out of the water for a total of 0.712 s.
In this time the salmon travels horizontally with a velocity of 7.2 m/s x cos 29 = 6.30 m/s
We can now calculate the horizontal distance tavelled by multiplying the horizontal velocity by the time spent out of water;
0.712 s x 6.30 m/s = 4.48 m
The "problem of perception" is best characterized as?
Answer:
making sense of a 3-d world from 2-d data
Explanation:
Pam rubs a balloon on her head to generate a static charge. She holds the balloon up against a wall. Which of the following describes the electric charges and forces at work if the balloon sticks to the wall?
Electrons move from Pam’s hair to the balloon and attract electrons in the wall.
Electrons move from Pam’s hair to the balloon and attract protons in the wall.
Protons move from Pam’s hair to the balloon and attract protons in the wall.
Protons in the balloon form chemical bonds with protons in the wall.
Answer:
c
Explanation:
If the balloon sticks to the wall then electrons move from Pam’s hair to the balloon and attract protons in the wall.
One of the ways of producing static electricity is by the use of friction. Friction occurs when two surfaces are rubbed together. This leads to the loss of electrons from one of the surface which attracts the protons on another surface.
If the balloon sticks to the wall then electrons move from Pam’s hair to the balloon and attract protons in the wall.
Learn more about static electricity:https://brainly.com/question/821085
A car traveling 85 km/h is 250 m behind a truck
traveling 73 km/h.
Time needed = t = 20.83 s
Further explanationGiven
car speed = 85 km/h
truck speed = 73 km/h
Required
the time it takes for the car to reach the truck
Solution
When the car reaches the truck, the distance between them will be the same
x car - 250 m = x truck
General formula for distance (d) :
d = v.t
So the equation becomes :
85t-250 = 73t
12t=250
t = 20.83 s
What is the difference between elastic PE and gravitational PE?
A plastic rod 1.6 m long is rubbed all over with wool, and acquires a charge of -9e-08 coulombs. We choose the center of the rod to be the origin of our coordinate system, with the x-axis extending to the right, the y-axis extending up, and the z-axis out of the page. In order to calculate the electric field at location A = < 0.7, 0, 0 > m, we divide the rod into 8 pieces, and approximate each piece as a point charge located at the center of the piece.
Solution :
Length of the plastic rod , L = 1.6 m
Total charge on the plastic rod , Q = [tex]$-9 \times 10^{-8}$[/tex] C
The rod is divided into 8 pieces.
a). The length of the 8 pieces is , [tex]$l=\frac{L}{8}$[/tex]
[tex]$=\frac{1.6}{8}$[/tex]
= 0.2 m
b). Location of the center of the piece number 5 is given as : 0 m, -0.09375 m, 0 m.
c). The charge q on the piece number 5 is given as
[tex]$q=\frac{Q}{L}\times l$[/tex]
[tex]$q=\frac{-9 \times 10^{-8}}{1.6}\times0.2$[/tex]
= [tex]$-1.125 \times 10^{-8}$[/tex] C
d). WE approximate that piece 5 as a point charge and we need to find out the field at point A(0.7 m, 0, 0) only due to the charge.
We know, the Coulombs force constant, k = [tex]$8.99 \times 10^9 \ N.m^2/C^2$[/tex]
So the X component of the electric field at the point A is given as
[tex]$E_x = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \cos \frac{187.628}{0.70625}$[/tex]
= -126.15 N/C
The Y component of the electric field at the point A is
[tex]$E_y = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \sin \frac{187.628}{0.70625}$[/tex]
= -16.93 N/C
Now since the rod and the point A is in the x - y plane, the z component of the field at point A due to the piece 5 will be zero.
∴ [tex]$E_z=0$[/tex]
Thus, [tex]$E= <-126.15,-16.93,0>$[/tex]
What is measurement ?
Predictions about the future based on the position of planets is an example of
- physics
- biology
- earth science
- pseudoscience
Answer:
astronomi
Explanation:
sciemce ya ya
Someone please help me, I’m so lost my brain hurts
-- It takes 100 calories of heat to make 10 grams of the stuff 20° warmer.
How much of the heat warms each gram ?
-- It takes 10 calories of heat to make each gram of the stuff 20° warmer.
How much of the heat warms that gram each degree ?
-- It takes 1/2 calorie of heat to make each gram of the stuff 1° warmer.
The specific heat of that stuff is
(1/2 calorie) per gram per °C.
That's choice-3 .
Explanation:
The answer is No. 3
0.5 cal/g°C
What is the mass of an object if it is moving at a speed of 10 m/s and has 400 J of kinetic energy?
Answers:
8 kg
Explanation:
Kinetic Energy = (mass × velocity × velocity) ÷ 2
We know that Kinetic Energy = 400 J and velocity = 10 m/s.
KE = (m × v × v) ÷ 2
400 J = (m × 10 m/s × 10 m/s) ÷ 2
400 J = m × 50 m^2/s^2
To find the mass you will divide 400 J and 50 m^2/s^2.
m = 8 kg
You can also check it if it gives you 400 J.
KE = (m × v × v) ÷ 2
KE = (8 kg × 10 m/s × 10 m/s) ÷ 2
KE = 400 J
So this means that the mass is 8 kg. I know that it is a bit confusing, but when you do J (joules) ÷ m^2/s^2 = kg (kilograms). Hope this helps, thank you !!
The surface area of a postage
stamp is 0.00600 m^2, and the air
exerts 1.00 atm of pressure on it.
How much force does it exert on
the stamp?
(Hint: The standard unit for
pressure is Pa.)
(Unit = N)
Answer:
Force = 607.95 Newton
Explanation:
Given the following data;
Area = 0.00600 m^2
Pressure = 1 atm to Pascal = 101325 Pa
To find the force;
Pressure = Force/area
Force = pressure * area
Substituting into the equation, we have;
Force = 101325 * 0.00600
Force = 607.95 Newton.
Therefore, the amount of force exerted by the air on the stamp is 607.95 Newton.
Which plate is the South American plate?
Answer:
The south American plate