kepler was the first to be credited for discovering that planets follow

The time taken for the coffee to cool from 93°C to 73°C is approximately 36.1 minutes.

The cooling law is given by:

$$\frac{dQ}{dt}=-k(T-T_0)$$

where Q is the heat in the object, t is the time taken, T is the temperature of the object at time t, T0 is the temperature of the environment and k is a constant known as the cooling constant.

We need to find the time it takes for the coffee to reach a drinking temperature of 73°C given that its initial temperature is 93°C.

Therefore, we need to find the time it takes for the coffee to cool down from 93°C to 73°C when placed in a room temperature of 18°C.

Let’s assume that the heat energy that is lost by the coffee is equal to the heat energy gained by the environment. We can express this as:

dQ = - dQ where dQ is the heat energy gained by the environment.

We can substitute dQ with C(T-T0) where C is the specific heat capacity of the object.

We can rearrange the equation as follows:

$$-\frac{dQ}{dt}=k(T-T_0)$$

$$-\frac{d}{dt}C(T-T_0)=k(T-T_0)$$

$$\frac{d}{dt}T=-k(T-T_0)$$

The differential equation above can be solved using separation of variables as follows:

$$\frac{d}{dt}\ln(T-T_0)=-k$$

$$\ln(T-T_0)=-kt+c_1$$

$$T-T_0=e^{-kt+c_1}$$

$$T=T_0+Ce^{-kt}$$

where C = e^(c1).

We can now use the values given to find the specific value of C which is the temperature difference when t=0, that is, the temperature difference between the initial temperature of the coffee and the room temperature.

$$T=T_0+Ce^{-kt}$$

$$73=18+C\cdot e^{-0.09t}$$

$$55=C\cdot e^{-0.09t}$$

$$C=55e^{0.09t}$$

$$T=18+55e^{0.09t}$$

We can now solve for the value of t when T=93 as follows:

$$93=18+55e^{0.09t}$$

$$e^{0.09t}=\frac{93-18}{55}$$

$$e^{0.09t}=1.3636$$

$$t=\frac{\ln(1.3636)}{0.09}$$

Using a calculator, we can find that the time taken for the coffee to cool from 93°C to 73°C is approximately 36.1 minutes.

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Answer:

2*F

Explanation:

If we put an object of a given size exactly at a distance 2*F from the lens, the virtual image (the image generated by the lens) will be generated at a distance 2*F from the lens and the size will be equal to the size of the real object (but the image will be inverted)

Now let's do the math.

The relation between the distance of the object to the lens O, and the distance between the image and the lens I is:

1/O + 1/I = 1/F

solving for O, we get:

1/O = 1/F - 1/I = (I - F)/(F*I)

O = F*I/(I - F)

Such that the relation between the height of the original object, H and the height of the virtual image H' is:

H/H' =  -I/O

Replacing by O we get:

H/H' = -I/(F*I/(I - F))

If the sizes are equal, then H/H' = - 1  (remember that the image is inverted, thus the sign)

-1 = -I/(F*I/(I - F))

F*I/(I - F) = I

F*I = (I - F)*I

F = (I - F)

F + F = I = 2*F

The distance between the image and the lens is 2*F

O =  F*I/(I - F) = F*2*F/(2*F - F) =  2*F

The object is at a distance 2*F from the lens.

Answer:

Yes

Explanation:

Answer:

m = 60 [kg] (mass on the moon)

Explanation:

We must remember that the mass is conserved, that is, it remains the same regardless of where it is located.

The only variation is the weight, which is different from the mass. Weight is determined by means of the product of mass by gravitational acceleration.

Therefore the mass of 60 [kg] on Earth will be the same mass on the moon.

The electrostatic force on A by B is 3.9 × 10⁻⁵ N and the force from C is -1.9× 10⁻⁵ N. Then the net electric  force acting on A is 5.8 × 10⁻⁵ N.

According to Coulomb's law of force, the electrostatic force between two charges separated by a distance of r is given as follows:

Fc = Ke q1 q2 /r²

where Ke = 8.9 × 10⁹ Nm²/C²

Given the charge of  A = 2.5 × 10⁻⁹ C

charge of B = 1 × 10⁻⁹ C

distance r = 7.50 cm = 0.075 m

then Fc =  8.9 × 10⁹ Nm²/C²  (2.5 × 10⁻⁹ C ) (1 × 10⁻⁹ C)/(0.075 m)² = 3.9 × 10⁻⁵ N

Similarly, the force on A by the charge C is calculated as follows:

distance to C = 0.075 m + 0.075 = 0.15 m

charge of C = - 17.5 × 10⁻⁹ C.

Then Fc =   8.9 × 10⁹ Nm²/C²  (2.5 × 10⁻⁹ C ) (-17.5× 10⁻⁹ C)/(0.075 m)² = - 1.9 × 10⁻⁵ N

The net electric force acting on A =  3.9 × 10⁻⁵ N - (-1.9 × 10⁻⁵ N) = 5.8 × 10⁻⁵ N.

Therefore, the net electric force acting on A is  5.8 × 10⁻⁵ N.

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The diameter of the output line of a hydraulic lift that can generate a maximum gauge pressure of 17 atm and lift a maximum mass of 8730 kg is 80.1 cm².

To calculate the diameter of the output line, we use the formula: pressure = force / area

where force is the weight of the mass being lifted, and area is the cross-sectional area of the output line. First, we convert the maximum weight the hydraulic lift can lift from kg to N (newtons): force = mass x gravity

force = 8730 kg x 9.81 m/s² = 85,556.5 N

Now we can calculate the area of the output line using the formula:

area = force / pressure

area = 85,556.5 N / 17 atm = 5,032.2 cm²

To convert the area to cm, we use the formula:

1 cm² = 0.0001 m²

Therefore, the area in cm² is 503.22 cm². Finally, we calculate the diameter of the output line using the formula:area = π x (diameter/2)²

diameter = √(4 x area / π)

diameter = √(4 x 503.22 cm² / π) = 80.1 cm

Therefore, the diameter of the output line is 80.1 cm.

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Answer:

12.3°C should be the correct answer

Answer:

12.3

Explanation:

Answer:

Oceanic currents an waves are in motion due to energy of wind.

Explanation:

Explanation: It is because when a car is moving both the car and the driver is in inertia of motion. When a car is involved in collision it comes to a sudden stop and the car comes into inertia of rest whereas the person still in inertia of motion moves forward and might result in major injuries. But this can be prevented by wearing a seatbelt

Hope it helps :)

Answer:

leekwwjwojowo cliiiodh

Explanation:

Answer:

A free body diagram consists of a diagrammatic representation of a single body or a subsystem of bodies isolated from its surroundings showing all the forces acting on it In physics and engineering, a free body diagram (force diagram, or FBD) is a graphical illustration used to visualize the applied forces, moments,

Explanation:

Hope it helps

Answer:

12 ml

Explanation:

The thing to remember about a substance's density is that it tells you the mass of every unit of volume of said substance.

Answer:

During the evening, the land cools off more quickly than the water. The cooler land cools the air above it, while the warmer water warms the air above it. These differences in air temperature create the convection.

Explanation:

sorry I took forever

Great Falls, Montana is located in the northern part of the United States, which means it is affected by continental air masses.

In the summer, Great Falls experiences warm and dry air masses, while in the winter, it experiences cold and dry air masses. These air masses can bring extreme temperature changes and weather conditions such as snowstorms and thunderstorms. Overall, the air mass over Great Falls can vary depending on the season and weather patterns.

However, in general, the air masses that affect Montana include continental polar (cP) and maritime polar (mP) air masses. Continental polar air masses originate from the cold and dry regions of central and northern Canada, while maritime polar air masses come from the Pacific Ocean and are typically cold and moist.

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The force of friction acting on him is 122 N. The correct answer is option C

Friction is a force that opposes the motion of a static or a moving object.

Given that Barry slides across an icy pond. The coefficient of kinetic friction between his shoes and the ice is 0.15. If his mass is 83 kg

The given parameters are;

The normal reaction N on the body = mg

N = 83 x 9.8

N = 813.4 N

The Frictional force formula is  \(F_{r}\) = μN

\(F_{r}\) = 0.15 x 813.4

\(F_{r}\) = 122.01 N

Therefore, the force of friction acting on him is 122 N approximately.

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Jenny can:

1).  Define what she means by "better".

2).  Take 20 T-shirts, all sullied by a wide variety of types of dirt, soil, schmutz, grime, dust, soot, mud, filth, mire, sludge, slime, ooze, dross, waste, stains, crud, grunge, and yuck.

3).  Close her eyes, and, by feel alone, select 10 T-shirts out of the 20.

4).  Wash 10 shirts with her old detergent.  Wash 10 other shirts with her new detergent.  After washing, keep the two groups of shirts segregated in separate piles.

5).  Invite 5 of her closest friends to her house for soda and chips.

After snacks, tell them she needs their opinions.  Don't tell them anything about the detergents.

Put the two piles of T-shirts on a large table.

Tell them what "better" or "cleaner" means to her.

Let each friend feel, palpate, inspect, evaluate and examine the two piles, and the T-shirts in each pile, being careful not to mix the piles.

6).  Finally, ask each friend which pile of shirts s/he thinks more closely meets Jenny's definition of "cleaner" or "better".

Answer:

79.8 is the answere

I hope this HELP :)

Explanation:

Here, initial velocity is u=18.5m/s and final velocity is v=46.1m/s

Time taken t=2.47s

If a be the acceleration of the car.

Using v=u+at,

46.1=18.5+a(2.47)

⟹ a=11.17m/s

2

If d be the distance traveled by car.

Using formula v

2

−u

2

=2ad,

(46.1)

2

−(18.5)

2

=2(11.17)d

⟹ d=79.8m

Answer:

12m/s

Explanation:

Using the equation of  motion

v = u + at

Given that

u = 0m/s

a = 2m/s²

time t = 6s

Substitute the given values into the expression

v = 0 + 2(6)

v = 0+12

v = 12m/s

Hence the required velocity is 12m/s

The height of the mirror should be at least 1.87 m above the floor.  Therefore, the height of the mirror should be at least 1.87 m above the floor to allow the man to see both the top of his head and his feet.


To find the height of the mirror, we need to consider the line of sight from the man's eyes to the top of his head and feet. The distance from the man's eyes to the top of his head is 0.11 m. So, the line of sight from his eyes to the top of his head is at an angle of 90 degrees. Now, we need to find the angle of depression from his eyes to his feet. The distance from his eyes to the floor is 1.76 m. The distance from his feet to the floor can be found by subtracting the height of his eyes from the height of his head: 0.11 m.
Using the tangent function, we can find the angle of depression:
tan(angle of depression) = (height of feet - height of eyes) / distance from eyes to the floor
tan(angle of depression) = (0.11 m - 1.76 m) / distance from eyes to the floor
tan(angle of depression) = -1.65 m / distance from eyes to the floor
To find the height of the mirror, we need to find the distance from the eyes to the floor when the angle of depression is 90 degrees. So, we can set up the equation:
tan(90 degrees) = -1.65 m / distance from eyes to the floor
Since tan(90 degrees) is undefined, the distance from the eyes to the floor when the angle of depression is 90 degrees is infinite.

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The original speed of the bullet is 365.73 m/s

Initial velocity of the block is zero

and that o block -bullet after velocity is 0.73 m/s

Applying law of conservation of momentum:

Initial momentum = final momentum

mV(bi) + MV(wi) = mV(b) + MV(wf)

where m = mass of bullet = 10 g = 10^−2 ∣kg

M = mass of wood block = 5 kg

V(bI) = initial mass of bullet

V(wi) = initial mass of wood block

and V(bf) = V(wf) = 0.73 m/s

10^−2V(bi) + 0(10^−2 + 5)0.73

V(bi) = 5.01 × 0.73/10^−2

V(bi) = 365.73 m/s

Hence, the original speed of the bullet is 365.73 m/s

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The three spheres' total charge will thus be A / (1/2). B: 0, C:0 A: 9, B:-1,C: 9\b. A: 1/2 B: 0, C:

This indicates that the two spheres receive an equal distribution of the charge.

First off, we have:

Charge on sphere A

Sphere B: -q/2 charge

Sphere C: zero charge

Sphere B is initially contacted by sphere C. Since the two spheres' combined charge was.

When two conducting spheres come into contact, the charge is divided between them, making their potential equal.

V₁ = V2 8 = 8/2

where Q stands for the charge and C for the sphere's capacitance. The capacitance is the same for identical spheres, hence the preceding equation becomes Q1 = Q2.

Sphere B is initially contacted by sphere C. Given that the two spheres' combined charge was

- q/2 + 0 = - q/2

Each sphere will have a charge after contact that is half of this value:

q B = q C = (-q/2) * (1/2) = (-q/4)

Sphere A (charge of +q) is then touched by sphere C (charge of -q / 4). The total charge is therefore -q/4 + q = q*3/4.

Since the charge is evenly distributed, each sphere will get half of it:

Q A = Q C = Q_ = 1/2 * (3/4 * Q) = Q_ =

The three spheres' ultimate charge will thus be spherical was

q + 0 = q

Each sphere will have a charge after contact that is half of this value:

Q A = Q C = Q/2 = 1/2 * Q

Sphere B (charge of -q/2) is then touched by sphere C (charge of q/2). Thus, the total charge is equal to -q/2 + q/2/2.

. Thus, the total charge is equal to -q/2 + q/2/2 = 0.

Each sphere will get half of this charge since the charge is distributed equally, which translates to a charge of zero:

q {B} = q {C} = 0

The three spheres' total charge will thus be A / (1/2). B: 0, C:0 A: 9, B:-1,C: 9\b. A: 1/2 B: 0, C:

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Answer:

1 deg C = 5/9 deg F         (Ex. 212 F - 32) * 5/9 = 100

So deg F = 9/5 deg C = 9/5 * 2.9 = 5.2 deg F

Answer:

G.P.E  = 414050 Joules or 414.05 Kilojoules

Explanation:

Given the following data;

Mass = 65 kg

Height = 650 m

We know that acceleration due to gravity is equal to 9.8m/s²

To find the gravitational potential energy;

Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.

Mathematically, gravitational potential energy is given by the formula;

\( G.P.E = mgh\)

Where;

Substituting into the equation, we have;

\( G.P.E = 65 * 9.8 * 650 \)

\( G.P.E = 414050 \)

G.P.E  = 414050 Joules or 414.05 Kilojoules.

Answer:

The equivalent resistance of the parallel circuit would be 20 Ω

Explanation:

To calculate the resistance of resistors connected in parallel, the formula to be used is

1/R = 1/R₁ + R₂ + R₃ + R₄...

1/R = 1/120 + 1/60 + 1/40

1/R = (1 + 2 + 3)/120

1/R = 6/120

1/R = 1/20 Ω

This can be rewritten or cross-multiplied to be

R × 1 = 20 × 1

R = 20 Ω

The equivalent resistance (R) would then be 20 Ω

Explanation:

the figure in the left side has higher frequency.

because it has more nos. of wave in 1sec.

Answer:

The plane goes for 600 km per hour.

The trip from a city to another is 2.5 hours

Basically, all you have to do is multiply 600 by 2.5.

That’s 1,500 kilometres.

Explanation:

A plane's average speed between two cities is 750 km/hr and if the trip takes 2.5 hours then the total distance covered by the plane would be 1875 kilometers.

The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object.

As given in the problem, a plane's average speed between two cities is 750 km/hr and if the trip takes 2.5 hours then we have to find out  the total distance covered by the plane,

The plane's average speed between two cities is 750 kilometers/hour,

time is taken in the whole trip = 2.5 hours

The distance covered by the plane =  750 kilometers/hour×2.5 hours

                                                          = 1875 kilometers

Thus, the total distance covered by the plane would be 1875 kilometers.

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