What mistake did Farah make in this experiment? Farah conducted the following experiment to check whether fabrics of different colours take different times to dry. She took one piece each of red, white and blue cotton. They were all of the same size and quality. She wet each piece with the same amount of water and hung them from spring balances near a fan as shown above. She noted the weight of each piece of cotton. She then put the fan on and noted the weight of each piece of cotton at the end of every two minutes. The weight of all the pieces of cotton decreased as water evaporated from the them.​

The power used, given that a force of 20 N is used to push the shopping cart 3.5 m in 2 seconds is 35 W

First, we shall determine the work done in pushing the cart. Details below:

Wd = Fd

Wd = 20 × 3.5

Wd = 70 J

Finally, we shall determine the power used in pushing the cart. Details below:

P = Wd / t

P = 70 / 2

P = 35 W

Thus, we can conclude that the power used is 35 W

Learn more about power:

https://brainly.com/question/30817666

#SPJ1

Answer: C

Explanation: i have played sports in my life now i am no physics person but in order to follow the rules you have  to be a team player. and a part of being a team player is being positive and so b=a*d  

Answer:

Usbe

Explanation:

Answer:

This is what gives the Ionosphere its name and it is the free electrons that cause the reflection and absorption of radio waves. ... The high frequency waves pass through the ionosphere and escape into space while the low frequency waves reflect off the ionosphere and essentially "skip" around the earth.

Explanation:

Answer:

The correct answer is 0.022

Divide the volume value by 1000

22 divided by 1,000 = 0.022

Explanation:

Hope this helps!! :))

Answer:

D) all of the above

Explanation:

All of the given choices are correct definition of what weight of a substance implies.

Weight is the vertical force on a body due to the gravitational attraction or pull.

  Weight  = mass x acceleration due to gravity

Mass of a body is directly proportional to its weight and so also is the gravity.

Mass is the amount of matter within a substance.

Weight is the force of gravity exerted by a body on another or a surface.

The reason why the weight of a body changes from place to place is mainly due to the gravitational pull

Answer:

true

Explanation:

The kinetic energy of a gas is directly proportional to the temperature of the gas.because temperature is the average kinetic energy of a substance

I hope this helps

Relationship between Position-time graph and Velocity-time graph:

A positive slope of position corresponds to an increase in velocity.

A constant slope of position corresponds to a constant velocity.

A negative slope of position corresponds to a decrease in velocity.

A zero slope of position corresponds to a zero velocity.

Let us sketch the velocity-time graph as per the above rules.

Relationship between Velocity-time graph and Acceleration-time graph:

A positive slope of velocity corresponds to a positive acceleration.

A constant slope of velocity corresponds to a zero acceleration.

A negative slope of velocity corresponds to negative acceleration.

Let us sketch the acceleration-time graph as per the above rules.

The object with the greatest kinetic energy is the locomotive engine (option C)

To know the object with the greatest kinetic energy, we shall determine the kinetic energy of each objects. Details below:

For truck:

KE = ½mv²

KE = ½ × 3500 × 30²

KE = 1575000 J

For baseball:

KE = ½mv²

KE = ½ × 0.5 × 46.9²

KE = 549.90 J

For locomotive:

KE = ½mv²

KE = ½ × 205000 × 5²

KE = 2562500 J

For person:

KE = ½mv²

KE = ½ × 73 × 6²

KE = 1314 J

From the above calculations, we can see that the locomotive has the greatest kinetic energy. Thus, the correct answer is option C

Learn more about kinetic energy:

https://brainly.com/question/7981774

#SPJ1

Answer:

Height = 122.5 m

Speed = 49 m/s²

Explanation:

Thanks for the question.

We will use second equation of motion.

We know, u = 0 (body falls from rest)

t = 5 (given)

a = 9.8 m/s² (acceleration due to gravity)

s = ut + 0.5 at²

s = 0.5 x 9.8 x 25 =  122.5

So, the height of the building is 122.5 m.

Now, v = u + at

v = 0 + 9.8 x 5 = 49 m/s²

Cheers

Hi there!

We can begin by summing the forces acting on the car.

Along the axis of the incline, the forces of friction and gravity are working. The force of friction points towards the top of the ramp, while the force of gravity works towards the bottom.

We can use trigonometry to determine the force due to gravity along the ramp.

\(F_g = Mg sin\theta\)

The force due to friction is equal to:
\(F_f = \mu N\)

The normal force is the vertical component of the force due to gravity, so:
\(F_f = \mu Mgcos\theta\)

Now, the combination of these two forces produces a component of the centripetal force. Drawing a diagram, we see that the true centripetal force is the HYPOTENUSE, while these forces sum up to its horizontal component along the ramp.

Therefore:
\(F_c sin\theta = Mgsin\theta - \mu Mgcos\theta\)

The centripetal force is equivalent to:
\(F_c = \frac{Mv^2}{r}\)

m = mass (kg)

v = velocity (m/s)
r = radius (m)

Rewrite:
\(\frac{Mv^2}{r}sin\theta = Mgsin\theta - \mu Mgcos\theta\)

Cancel out 'M'.

\(\frac{v^2}{r}sin\theta = gsin\theta - \mu gcos\theta\)

Rearrange to solve for 'r'.

\(r = \frac{v^2sin\theta}{gsin\theta - \mu gcos\theta}\)

Plug in values and solve.
\(r = \frac{(27.1^2)sin(29.1)}{(9.8)sin(29.1) - 0.4(9.8)cos(29.1)} = \boxed{266.365 m}\)

Answer:

de Broglie wavelength of the bullet is 3.093 x 10⁻³⁵ m

Explanation:

Given;

mass of bullet, m = 28 g = 0.028 kg

velocity of the bullet, v = 765 m/s

de Broglie wavelength of the bullet is given by;

λ = h / mv

where;

λ is de Broglie wavelength of the bullet

h is Planck's constant = 6.626 x 10⁻³⁴ J/s

λ = h / mv

λ = (6.626 x 10⁻³⁴ ) / (0.028 x 765)

λ = 3.093 x 10⁻³⁵ m

Therefore, de Broglie wavelength of the bullet is 3.093 x 10⁻³⁵ m

Hendry and Cathy will each throw an object, and the time and location at which they will collide can be determined using the laws of motion. Hendry's item had an initial velocity of 26.5 m/s, whereas Cathy's object had an initial velocity of 45 m/s. Hendry's object's equation of motion is given by: s = u*t + 0.5*a*t*2, where s is the displacement, u*t* is the starting velocity, t* is the time, and a*t* is the acceleration brought on by gravity.

The acceleration caused by gravity is negative since the item is being flung upward. The item that Cathy threw has the following equation of motion: s = u * t - 0.5 * a * t2.where s is the distance travelled, u is the starting speed, t is the passage of time, and an is the acceleration brought on by gravity. The acceleration caused by gravity is negative since the item is being flung upward.

These equations allow us to determine the location and timing of the two items' collision. By figuring out the two equations for t, one may determine the moment when the objects will collide. By changing the value of t in either equation, one may determine the distance at which the objects will collide. Therefore, using the equations of motion, it is possible to determine the moment and distance at which the two objects will collide.

Learn more about  velocity  at:

https://brainly.com/question/17127206

#SPJ1

Answer:

the anwser is 90

Explanation:

because 140-50=90

The terminal velocity of the sphere is approximately 22.68 mph.

The terminal velocity of a sphere is the constant speed at which the gravitational force pulling the sphere down is balanced by the drag force pushing the sphere up. The drag force is proportional to the velocity of the sphere, and can be calculated using the following formula:

Fd = (1/2) * rho * Cd * A * v²

where Fd is the drag force, rho is the density of the fluid (air in this case), Cd is the drag coefficient (which depends on the shape of the object), A is the cross-sectional area of the object perpendicular to the direction of motion, and v is the velocity of the object.

The gravitational force pulling the sphere down is given by:

Fg = m * g

where m is the mass of the sphere and g is the acceleration due to gravity.

At terminal velocity, the drag force is equal in magnitude to the gravitational force, so:

Fd = Fg

Substituting the expressions for Fd and Fg and solving for v, we get:

v = √((2 * m * g) / (rho * Cd * A))

where A = pi * r² is the cross-sectional area of the sphere, and r is the radius of the sphere.

Plugging in the given values, we get:

v = sqrt((2 * 0.6 * 9.81) / (1.2 * 0.47 * pi * 0.3²)) ≈ 10.13 m/s

To convert this to mph, we multiply by 2.23694:

v ≈ 22.68 mph

To know more about terminal velocity, here

brainly.com/question/2654450

#SPJ1

Answer:

The rate of change of velocity is acceleration. Like velocity, acceleration is a vector and has both magnitude and direction. For example, a car in straight-line motion is said to have forward (positive) acceleration if it is speeding up and rearward (negative) acceleration if it is slowing down.

Explanation:

Hope it is helpful....

Answer:

a)40 meters

b)2 m/s

c)2 m/s

d)0 m/s

e)45 degrees northeast

Explanation:

a) The displacement from C to A is the distance directly across the river, which is 40 meters.

b) The speed of the boat as seen by people standing at A is the magnitude of the boat's velocity vector, which is equal to the displacement divided by the time taken:

Speed = displacement / time = 40 m / 20 s = 2 m/s.

c) Let v be the speed of the water in the river. The boat is moving at right angles to the flow of the river, so the water exerts a perpendicular force on the boat. The time taken for the boat to travel from A to C is 20 seconds, during which time the boat will have been carried downstream by the river by a distance equal to v times the time taken.

Distance carried downstream = v × time = v × 20 m.

Since the boat landed at C, which is directly across the river from A, the distance it traveled horizontally is 40 meters. Therefore:

40 m = (boat speed) × (time taken) = (boat speed) × 20 s.

Hence, the speed of the boat is:

Boat speed = 40 m / 20 s = 2 m/s.

So, we have two equations:

Distance carried downstream = v × 20 m

Boat speed = 2 m/s

From the first equation, we get:

v × 20 m = 40 m

Therefore, the speed of the water in the river is:

v = 40 m / 20 m = 2 m/s.

d) The speed of the boat as seen by a fish drifting with the river is the difference between the speed of the boat and the speed of the water in the river:

Boat speed - Water speed = 2 m/s - 2 m/s = 0 m/s.

So, the speed of the boat as seen by a fish drifting with the river is zero.

e) The boat should head in a direction that makes its velocity vector point directly from A to B. Since A and B are directly opposite each other, this means the velocity vector should be perpendicular to the line connecting A and B.

We know the boat's velocity vector has a magnitude of 2 m/s and is at right angles to the velocity vector of the water in the river, which has a magnitude of 2 m/s. So, we can draw a vector diagram with the velocity vector of the boat pointing straight up and the velocity vector of the water pointing straight to the right. The vector connecting the tail of the water velocity vector to the head of the boat velocity vector will then point directly from A to B.

The angle between the boat's velocity vector and the line connecting A and B can be found using trigonometry. Let θ be this angle. Then:

tan(θ) = (boat speed) / (water speed) = 2 m/s / 2 m/s = 1.

Taking the inverse tangent of both sides gives:

θ = tan^(-1)(1) = 45°.

So, the boat should head in a direction 45 degrees to the right of straight up, or northeast.

Answer:  I believe that it is 35 Joules.

Explanation:

100 - 65 = 35

:)

Answer:3000

Explanation:

given:u=0v=20m/st= 8sec

thereforea=v-u/t=20-0/8=20/8=5/2 m/som=1200 kg

thereforef=ma=1200*5/2=600*5=3000N

The power output is given 2000 watt and voltage is 240 v. Then the current through the heating element is 8.3 A and the resistance is 29 ohms.

The power used by an object is the rate of its work done or energy. It is the energy divided by time. The power output in a circuit is the product of the potential difference V and current I.

P = I V

Given,

P = 2 kw = 2000 W

v = 240 V.

Then I = P/v

I = 2000 w/240 v = 8.3 A.

According to Ohm's law, voltage v is the product of the current and resistance through the material.

hence,

V = I R

then, R = V/I

R = 240 V/8.33 A

  = 29 Ω.

Therefore, the current and resistance through the heating element are 8.3 A and 29 ohms respectively.

Find more on power;

https://brainly.com/question/24110214

#SPJ9

No Solution:

4x+10y = 40

2x + 5y = 40

2x - 8y=17

x - 4y = 7

One Solution:

2y - X= 12

2y - 2x =10

x + 10y =50

2x + 10y =90

Infinitely Many Solutions:

x + 2y = 1

3x + 6y= 3

2y - 3x = 5

2/5y -3/5x =1

Explanation: You only had 11 equations listed. But I believe these are the ones you want. I took the test and got them right. Hope it helps

Answer:

Displacement

Explanation:

I think Sam's mom isn't worried with how far away he goes, but will be upset if he isn't home fast enough for dinner.

As thermal energy is added to a sample of water, the potential energy of its molecules increases, and then the kinetic energy of its molecules increases.

The sections of the heating curve illustrate this process  is B followed by D

Therefore option A is correct.

Thermal energy (also called heat energy) is described as being produced when a rise in temperature causes atoms and molecules to move faster and collide with each other.

some factors of thermal energy include:

Learn more about thermal energy at: https://brainly.com/question/934320

#SPJ1

Answer:

4sec

Explanation:

Since we know the initial velocity=0, acceleration = -4; and the displacemnt =14, we use the equation d = vi • t + ½ • a • t2. So, just plug in the values and solve for t in this case it's 4 sec

A body is said to be in freefall when it moves solely under the influence of  gravity.

The time it took for the ball to crash at the surface = 3 sec.

acceleration of gravity on the moon is 4 m/s^2.

the height of 14 m.

The formula for free fall:

\(h= \frac{1}{2}gt^2\)

t^2 = 2h /g = 2 x 14 /4 = 7

t = \(\sqrt{7} = 2.65\) sec ≅ 3 sec.

The time it took for the ball to crash at the surface = 3 sec.

To learn more about :   freefall

Ref : https://brainly.com/question/12167131

#SPJ2

Answer:

The force on each wire is  

   \(T_1  = 12.5 \ N  \)

     \(  T_2  =   25 \  N  \)

    \(  T_3  =  50  \  N  \)

Explanation:

From the question we are told that

   The acceleration at which the elevator will stop is  \(a =  \frac{g}{4}\)

    The weight of each section of the wire is  \(W =  \ 10 \ N\)

Generally \(W_1 = W_2 = W_3\) here  \(W_1 , W_2 , W_3\) are weight at each section

Generally considering the first section, the force acting along the y-axis  is mathematically represented as

       \(\sum F_y_1 =  T_1 - W_1 =  m *  a\)

Here \(T_ 1\) represents the tension on the wire at the first section while  \(W_1\) represents the weight  of the lamp at the first section

So

      \(T_1  - 10 = m *  \frac{g}{4}\)

=>    \(T_1  - 10 =  \frac{W_1}{4}\)

=>    \(T_1  - 10 =  \frac{10}{4}\)

=>    \(T_1  = 12.5 \ N  \)

Generally considering the second section, the force acting along the y-axis  is mathematically represented as

      \(\sum F_y_2 =  T_2 -T_1- W_2 =  m *  a\)

=>   \(  T_2 - T_1- 10 =  m *  \frac{g}{4}\)

=>   \(  T_2 - 12.5- 10 =    \frac{W_2}{4}\)

=>  \(  T_2- 12.5- 10 =    \frac{10}{4}\)

=>   \(  T_2  =   25 \  N  \)

Generally considering the third  section, the force acting along the y-axis  is mathematically represented as

    \(\sum F_y_3 = T_3- T_2 -T_1- W_3 =  m *  a\)

    \(  T_3 - T_2 - T_1- 10 =  m *  \frac{g}{4}\)

      \(  T_3 - 25 - 12.5- 10 =    \frac{W_2}{4}\)

       \(  T_3 - 25 - 12.5- 10 =    \frac{10}{4}\)

       \(  T_3  =  50  \  N  \)

The student measured the length of a wire four times and the total length from the reading is 18.55 m.

From the given,

The length of the wire measured by the student using a meter rule is :

l₁ = 18.6 m

l₂ = 18.5m

l₃ = 18.6m

l₄ = 18.5 m

The total length of the wire is obtained from the average values of length.

Total length (L) = (l₁ + l₂ + l₃ + l₄)/4

                     L  = (18.6 + 18.5 + 18.6 + 18.5) / 4

                         = 74.2 /4

                         = 18.55

Hence, the actual length of the wire = 18.6 m.

To learn more about the length of the wire:

https://brainly.com/question/14633287

#SPJ1

Answer:

144.6ohms

Explanation:

v=IR

R =V/I=120/0.83

R=144.6

Explanation:

The orbiting period of a satellite at a height h from earth' surface is

T=2πr32gR2

where r=R+h.

Then, T=2π(R+h)R(R+hg)−−−−−−−−√

Here, R=6400km,h=1600km=R/4

T=2πR+R4−−−−−−√R(R+R4g)−−−−−−−−−⎷=2π(1.25)32Rg−−√

Putting the given values,

T=2×3.14×(6.4×106m9.8ms−2)−−−−−−−−−−−−√(1.25)32=7092s=1.97h

Now, a satellite will appear stationary in the sky over a point on the earth's equator if its period of revolution around the earthh is equal to the period of revolution of the earth up around its own axis whichh is 24h. Let us find the height h of such a satellite above the earth's suface in terms of the earth,'s radius.

Let it be nR.Then

T=2π(R+nR)R(R+nRg)−−−−−−−−−−√

=2π(Rg)−−−−−√(1+n)32

=2×3.14(6.4×106m/s9.8m/s2)−−−−−−−−−−−−−−−⎷(1+n)32

(5075s)(1+n)32=(1.41h)(1+n)32

For T=24h, we have (24h)=(1.41h)(1+n)32

or (1+n)32=241.41=17

or 1+n(17)23=6.61

or n=5.61

The height of the geostationary satellite above the earth's surface is nR=5.61×6400km=6.59×104km.

Answer:

4.80 m

Explanation:

We are given the mass of the high jumper, its initial velocity, and the acceleration of gravity. We are trying to find the vertical displacement of the high jumper.

Let's set the upwards direction to be positive and the downwards direction to be negative.

List out the relevant known variables.

We still need one more variable in order to use the constant acceleration equations. Since we are trying to find the max height of the jumper, we can use the fact that at the top of its trajectory, its final velocity will be 0 m/s.

    4. v = 0 m/s

Using these four variables, let's find the constant acceleration equation that contains these variables:

Substitute the known values into the equation and solve for Δx.

The high jumper can jump to a max height of 4.80 m.