Collaborative learning activities:__________.
A) Can empower students
B) Can give students ownership of their learning
C) Allow students and teachers to become partners in learning
D) Are best facilitated in lecture halls

Answer:

Explanation:

Friction causes generation of heat and causes increased wear and tear.

The friction is a resistive force and is related to heat energy, so an increase in friction results in the generation of heat, so option D is correct.

Two solid objects cannot roll or slide over one another due to the force of friction. Although frictional forces can be useful, such as the traction needed to walk without slipping, they can also present a large degree of resistance to motion. Automobile engines need about 20% of their power to overcome frictional forces in moving parts.

The fundamental source of friction between metals appears to be the adhesion forces between the contact zones of the surfaces, which are always microscopically uneven. Friction is produced by shearing, these "welded" seams, and the rubbing action of the rougher, tougher surface against the softer, smoother surface.

The friction is a resistive force trying to oppose the force applied As friction is related to heat when we increase the heat, the friction increases, and vice versa.

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Answer:

The magnitude and direction of the force per unit length of one wire on the other is 2 x 10⁻⁵ N/m, attractive force.

Explanation:

Given;

distance between the two parallel wires, r = 10 cm = 0.1 m

current in the first wire, I₁ = 2A

current in the second wire, I₂ = 5 A

The force per unit length on each wire can be calculated as;

[tex]\frac{F}{L} = \frac{\mu_oI_1I_2}{2\pi r}[/tex]

where;

μ₀ is permeability of free space = 4π x 10⁻⁷ m/A

[tex]\frac{F}{L} = \frac{\mu_oI_1I_2}{2\pi r} \\\\\frac{F}{L} = \frac{4\pi*10^{-7}*2*5}{2\pi *0.1} \\\\\frac{F}{L} = 2 *10^{-5} \ N[/tex]/ m

The direction of the force between the two wires is attractive since the current in the two wires are in opposite direction.

Therefore, the magnitude and direction of the force per unit length of one wire on the other is 2 x 10⁻⁵ N/m, attractive force.

Answer:

This statement is not true

Explanation:

Because The normal magnetic field line points out from the north magnetic pole and in from the south magnetic pole.

Answer:

false

Explanation:

hope this helps :)

Answer:

The answer is B.

Explanation:

Given that the current (Ampere) in a series circuit is same so we can ignore it. We can assume that the total voltage is 60V and all the 3 resistance are different, 20Ω, 40Ω and 60Ω. So first, we have to find the total resistance by adding :

Total resistance = 20Ω + 40Ω + 60Ω

= 120Ω

Next, we have to find out that 1Ω is equal to how many voltage by dividing :

120Ω = 60V

1Ω = 60V ÷ 120

1Ω = 0.5V

Lastly, we have to calculate the voltage at R1 so we have to multiply by 20 (R1) :

1Ω = 0.5V

20Ω = 0.5V × 20

20Ω = 10V

Answer:

See below

Explanation:

We know that the unit of pressure is Pascal.

We have,

Pressure = [tex] \frac{force}{area} [/tex]

[tex] = \frac{m \times g}{l \times b} [/tex]

[tex] = \frac{kg \: \times \: {meter \: per \: second \: }^{2} }{ {m}^{2} } [/tex]

[tex] = kg \: {m}^{ - 1} \: {s}^{ - 2} [/tex]

The unit of pressure i.e Pascal is derived unit because it is expressed depending on more than two units i.e kg / [ m × s × s ]

Hope this helps..

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Explanation:

Power = work / time

Power = force × distance / time

P = (650 kg) (10 m/s²) (20 m) / (15 s)

P = 8667 W

Answer:

52 g was lost as carbon dioxide to the atmosphere

Explanation:

When lead carbonate is heated, it decomposes into two components:

1. Lead oxide

2. carbon dioxide

While the lead oxide remains a yellow solid in the heating container, the carbon dioxide escapes into the atmosphere as a gas. The equation of the reaction is as below:

[tex]PbCO_3_{(s)} --> PbO_{(s)} + CO_2_{(g)}[/tex]

Hence, if a 150 g lead oxide is heated in a container and the final mass is 98 g, it means 52 g (150 - 98) of the total mass has been lost as carbon dioxide to the atmosphere.

Answer:

Explanation:

the resistance of a electrical device

R = V² / P where V is volt and P is power .

The devices are in parallel so same volt will apply on them

So R₁ = 12² / 32.5 = 4.431 ohm

R₂ = 12² / 2 x 10³ = .072 ohm

when they are in series

Common Current in them = 12 / 4.431 + .072

= 2.6649 A

power consumed by first device when they are in series

= current² x resistance

= 2.6649² x 4.431 = 31.46 W

power consumed by other

= 2.6649² x .072  = .511 W

Answer:

16 m

Explanation:

Given:

v₀ = 4 m/s

a = 4 m/s²

t = 2 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (4 m/s) (2 s) + ½ (4 m/s²) (2 s)²

Δx = 16 m

Answer:

0.572

Explanation:

First examine the force of friction at the slipping point where Ff = µsFN = µsmg.

the mass of the car is unknown,

The only force on the car that is not completely in the vertical direction is friction, so let us consider the sums of forces in the tangential and centerward directions.

First the tangential direction

∑Ft =Fft =mat

And then in the centerward direction ∑Fc =Ffc =mac =mv²t/r

Going back to our constant acceleration equations we see that v²t = v²ti +2at∆x = 2at πr/2

So going backwards and plugging in Ffc =m2atπr/ 2r =πmat

Ff = √(F2ft +F2fc)= matp √(1+π²)

µs = Ff /mg = at /g √(1+π²)=

1.70m/s/2 9.80 m/s² x√(1+π²)= 0.572

Answer:

Sa is the salary of the governor of state A

Sb  is the salary of the governor of state A

"The governor of state A earns $53,745 more than the governor of state B. "

This means that:

Sa = Sb + $53,745

"If the total of their salaries is $289,405,"

means that:

Sa + Sb = $289,405

Then we have two equations:

Sa = Sb + $53,745

Sa + Sb = $289,405

Now, we can replace the first equation into the second equation:

(Sb + $53,745) + Sb = $289,405

2*Sb = $289,405 - $53,745 = $235,660

Sb = ($235,660)/2 = $117,830

and:

Sa = Sb +  $53,745 =  $117,830 + $53,745 = $171,575

Governor of state A earns:  $171,575

Governor of state B earns:  $117,830

Answer:

59%

Explanation:

Data obtained from the question include the following:

Input temperature = 495 K

Output temperature = 293 K

Efficiency =?

The efficiency of the car engine can be obtained by multiplying the ratio of the output temperature to the input temperature by 100 as shown below:

Efficiency = output /input x 100

Efficiency = 293/495 x 100

Efficiency = 59.1 ≈ 59%

Therefore, the efficiency of the car engine is approximately 59%

Answer:

1.25x10^-19N

Explanation:see attached file pls

Answer:

20 m

Explanation:

Given in the y direction:

Δy = 10 m

v₀ = 25 m/s sin 37° = 15.0 m/s

a = -10 m/s²

Find: t

Δy = v₀ t + ½ at²

10 m = (15.0 m/s) t + ½ (-10 m/s²) t²

10 = 15t − 5t²

2 = 3t − t²

t² − 3t + 2 = 0

(t − 1) (t − 2) = 0

t = 1 or 2

Since the projectile reaches Q before it reaches the peak, we want the lesser time, so t = 1.

Given in the x direction:

v₀ = 25 m/s cos 37° = 20.0 m/s

a = 0 m/s²

t = 1 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (20.0 m/s) (1 s) + ½ (0 m/s²) (1 s)²

Δx = 20 m

If we launched a very fast dart from the Space Shuttle in a direction away from any planet, Assuming the dart is traveling at an extremely high speed (close to the speed of light), it might eventually encounter a cloud of interstellar gas or dust.

Space is mostly empty, consisting of a vacuum with very low density. However, space also contains various astronomical objects, such as stars, planets, moons, asteroids, comets, and other celestial bodies.

There is also interstellar gas and dust scattered throughout space, which can sometimes form clouds that give birth to new stars. Additionally, space is permeated by electromagnetic radiation, including cosmic rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.

Space also contains various forms of energy, including dark energy, which is believed to be responsible for the accelerating expansion of the universe, and dark matter, which is thought to make up the majority of the matter in the universe but cannot be directly observed. Overall, space is a vast and complex environment that continues to fascinate astronomers and scientists.

Here in this question,

Therefore, if launched a very fast dart from the Space Shuttle, is pointed in some direction away from any planet, it could travel beyond the solar system. it would be most likely to hit a cloud of interstellar gas or dust. first after traveling outward for a while.

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Answer:

The relative velocity of an object A with respect to another object B.

Explanation:

The relative velocity of an object A with respect to another object B is the velocity that object A would appear to have to an observer situated on object B moving along with it.

Answer:

2 hrs

Explanation:

time = distance ÷ speed

a).  frequency = (speed) / (wavelength)

The speed of light is around 3 x 10⁸ m/s.

For 380 nm (violet light), frequency = (3 x 10⁸ m/s) / (380 x 10⁻⁹ m)

Frequency = 7.89 x 10¹⁴ Hz

For 760 nm (red light), frequency = (3 x 10⁸ m/s) / (760 x 10⁻⁹/s)

Frequency = 3.94 x 10¹⁴ Hz

The ratio is 2 .

That's 1 octave, or 0.3 of a decade.

b).  The ratio of highest/lowest sounds is (20,000 Hz/20 Hz) = 1,000

That's 3 decades, or about 10 octaves.

===> Speaking logarithmically ( ! ), ears are sensitive to a range of sound frequencies that's 10 times as wide as the range of light frequencies that eyes can detect.

Answer:

Option d = all of the above.

Explanation:

This question is more of a driving lesson or tutorial Question and not that scientific, it is logical and the "rule" attached to reversing and driving that is operating of vehicles especially cars, trucks and so on.

All the options given in the Question from option 'a' to option 'c' are all correct when driving backwards that is reversing or backing . Driving backward(backing or reversing) is not as easy as during forward (drive mode).

=> " Position your right hand on the back of the passenger seat. Grip the steering wheel at the 12 o’clock position with your left hand"

REASON: FOR BALANCING.

=> " Move the wheel left or right in the direction in which you want the rear of the vehicle to go."

The above, given in the Question are all correct.

When backing straight or to the right, all of the mentioned options are correct and recommended practices are to Position your right hand on the back of the passenger seat. The correct option is option d.

a) Position your right hand on the back of the passenger seat: This is a technique used by some drivers to help them have a better sense of the vehicle's position and reference point while backing up.

b) Grip the steering wheel at the 12 o'clock position with your left hand: This hand position allows for better control and maneuverability of the steering wheel while backing up.

c) Move the wheel left or right in the direction in which you want the rear of the vehicle to go: This is the fundamental principle of steering while backing up. By turning the wheel in the desired direction, you can guide the rear of the vehicle in that direction.

Therefore, These practices can assist in improving control, visibility, and maneuverability while backing up, ensuring a safer and more effective backing maneuver. The correct option is option d.

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Answer: 17cm.

Explanation:

The equation you're using is:

Δd = df - di

Which means the change in position is equal to the final position minus the starting position. In this case that works out to 20cm - 3cm = 17cm. We're only interested in how much the snail moved, not how long it took to move, so even though they give a time it actually doesn't matter for this question.

Answer: The only advantage cutting crops with a sickle is that its very effective for cutting lodged crops.

Answer:

The time it will take for the object to hit the ground will be 4.

Explanation:

You have:

h(t)=−16t²+v0*t+h0

Being v0 the initial velocity (54 ft/s) and  h0 the initial height (40 ft) and replacing you get:

h(t)=−16t²+54*t+40

To know how long it will take for the object to touch the ground, the height h(t) must be zero. So:

0=−16t²+54*t+40

Being a quadratic function or parabola: f (x) = a*x² + b*x + c, the roots or zeros of the quadratic function are those values ​​of x for which the expression is 0. Graphically, the roots correspond to the points where the parabola intersects the x axis. To calculate the roots the expression is used:

[tex]\frac{-b+-\sqrt{b^{2}-4*a*c } }{2*a}[/tex]

In this case you have that:

Replacing in the expression of the calculation of roots you get:

[tex]\frac{-54+\sqrt{54^{2}-4*(-16)*40 } }{2*(-16)}[/tex]  Expresion (A)

and

[tex]\frac{-54-\sqrt{54^{2}-4*(-16)*40 } }{2*(-16)}[/tex] Expresion (B)

Solving the Expresion (A):

[tex]\frac{-54+\sqrt{5476 } }{2*(-16)}= \frac{-54+74}{2*(-16)}=\frac{20}{2*(-16)}=\frac{20}{-32}= -\frac{5}{8}[/tex]

Solving the Expresion (B):

[tex]\frac{-54-\sqrt{5476 } }{2*(-16)}= \frac{-54-74}{2*(-16)}=\frac{-128}{2*(-16)}=\frac{-128}{-32}= 4[/tex]

These results indicate the time it will take for the object to hit the ground can be -5/8 and 4. Since the time cannot be negative, then the time it will take for the object to hit the ground will be 4.

Answer:

4 seconds

Explanation:

i checked on the test and the other person was right give them brainliest

Answer:

Angle of refraction.

Explanation:

Refraction is simply a change in direction of light rays as it enters into another medium.

In the diagram given above, θ2 is simply the angle of refraction showing us that the light ray has changed direction as it moves from one medium to another medium.

The angle  θ2 is the angle that shows the degree of the bending of the light ray and is called the anglle of refraction.

The term refraction has to do with the bending of light rays as it crosss the boundary between two media. Now. we can see that the ray of ligh as shown in the image is undergoing refraction.

Now the angle that has been marked θ2 is the angle that shows the degree of the bending of the light ray and is called the anglle of refraction.

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Explanation:

m = kg. v=m/s. g=m/s^2. h= m

>>1/2mv^2=mgh

>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m

>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m>>kg m^2/s^2=kg m^2/s^2 the fraction 1/2 won't be able to make any changes to to the dimensional expression of energy i.e half of energy is still energy therefore you can neglect the number .

>>kg m^2/s^2=kg m^2/s^2

>>J= J

Answer:

yeah this statement is tru

Explanation:

it is because the speed of the bullet is more than the speed of rolling ball .so from this reason we cannot catch a bullet.

A bullet will be moving much faster than a rolling ball. Even seeing a bullet in flight requires it to be extremely low velocity.

Answer:

60 J of heat are released from the system: Q=-60 J

20 J of work is done on the system: W=-20 J

∆U=Q-W

∆U=-60-(-20)

∆U=-40 J

Explanation:

If the heat is released from the system, Q should be negative.

If the heat is gained by the system, Q should be positive.

If the work is done on the system, W should be negative.

If the work is done by the system, W should be positive.

Answer:

3360 N

Explanation:

In a first-class lever, the effort force and load force are on opposite sides of the fulcrum.

The lever is 5 m long.  The load force is 1.50 m from the fulcrum, so the effort force must be 3.50 m from the fulcrum.

The torques are equal:

Fr = Fr

(1440 N) (3.5 m) = F (1.5 m)

F = 3360 N

Answer:

2.5 kg/m³

Explanation:

Absolute pressure = gauge pressure + atmospheric pressure

P = Pg + Pa

The gauge pressure caused by the weight of a fluid is called the static pressure.  It is equal to the density of the fluid × acceleration due to gravity × depth of the fluid,

Pg = ρgh

Therefore:

P = ρgh + Pa

300 Pa = ρ (10 m/s²) (8.00 m) + 100 Pa

ρ = 2.5 kg/m³

Answer:

B. they have less mass than their reactants

Explanation:

In both nuclear fission and nuclear fusion, the products have less mass than their reactants. So, option B is correct.

Nuclear reaction is defined as the reaction that involves the collision between one or more atomic nuclei and a highly energetic subatomic particle to produce one or more nuclei along with the emission of a large amount of energy.

Here,

Nuclear fission and fusion are two types of nuclear reactions that involves the production of large amount of energy from atomic nuclei.

Nuclear fission is the nuclear reaction in which a heavier nucleus is split into two or more lighter nuclei, under radioactive condition, with the release of a massive amount of energy.

Nuclear fusion is the nuclear reaction in which two or more lighter nuclei nuclei fuse together under radioactive condition and forms a heavier nuclei and by releasing a large amount of energy.

In both nuclear fission and nuclear fusion, there occurs a release of large amount of energy. This is because most of the mass of the reactants is converted into energy which is known as the mass-energy. So the products of these nuclear reactions will have lesser mass than their reactants.

Hence,

In both nuclear fission and nuclear fusion, the products have less mass than their reactants.

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