a man walks 15 meters in 15 seconds. what is his speed​

Answer: Potential energy is at almost 0%, and kinetic energy is at almost 100%

Explanation: took the exam

The roller coaster will lost its potential energy when its starts to excite the vertical loop and its kinetic energy will be maximum. Hence, option D is correct.

Kinetic energy of a body is generated by its motion. Kinetic energy is proportional to the mass and square of the velocity of the object. Thus, as the speed of the object increase, kinetic energy increases.

Potential energy of a body is generated by virtue of its position. When a moving body slows down to stop, it gains potential energy and its kinetic energy starts decreasing.

When the roller coaster excites the vertical loop of the closed path, it loses its potential energy and  kinetic energy increases to maximum since its moving the down loop with greater velocity. Thus, option D is correct.

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Answer:

Neutral

Explanation:

The buoyant force balances the force of gravity when the average density of an object is equal to the density of the fluid in which it is immersed, resulting in the object sinking (if its density is greater than the density of the fluid) or rising (if it is less). Neutral buoyancy occurs when the average density of an object equals the density of the fluid in which it is immersed. There is no sinking or rising for an object with neutral buoyancy.

Answer:

it is B

Explanation:

it is a compound lol

The kinetic energy is calculated by work done, The work done is equal to the change in kinetic energy when the object is at rest.

Kinetic energy (KE) is calculated using the formula:

KE = (1/2) × mass × velocity²

However, if you don't have the velocity value, it is not possible to calculate the kinetic energy accurately. Velocity is a crucial component in determining kinetic energy because it quantifies the object's speed and direction of motion.

But there is a special case when the object is at rest the change in velocity is equal to the work done.

Therefore, The kinetic energy is calculated by work done, The work done is equal to the change in kinetic energy when the object is at rest.

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Explanation:

When you pull the sock off of the blanket, the socks gain electrons out of blanket. This makes socks slightly negatively charged. The potential energy of the socks rise whereas potential energy of the blanket reduces. This happens because of exchange of electrons between socks and blanket.

Answer:

Average speed is 60 km/hr whereas average velocity is 0 km/ hr.

Explanation:

The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.

Answer:

In a machine, friction reduces the mechanical advantage, or the ratio of output to input: an automobile, for instance, uses one-quarter of its energy on reducing friction. Yet, it is also friction in the tires that allows the car to stay on the road, and friction in the clutch that makes it possible to drive at all

Explanation:

hope it will help you

Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat deals with the flow of thermal energy. Temperature is the physical manifestation of thermal energy, and deals with whether it feels cold or hot. 

Answer:

because the lumps are just baking soda covered with whatever watery substance you used.

Explanation:

so pretty much inside the lumps is just a bunch of baking soda

Answer:

6. Speed = 76.8 m/s

7. Frequency = 1372 Hz

Explanation:

Given the following data;

6. Frequency = 384 Hz

Wavelength = 20 cm to meters = 20/100 = 0.2 m

To find the speed of sound;

Speed = wavelength * frequency

Speed = 0.2 * 384

Speed = 76.8 m/s

7. Wavelength = 25 cm to meters = 25/100 = 0.25 m

Speed = 343 m/s

To find the frequency of the turning fork;

Frequency = speed/wavelength

Frequency = 343/0.25

Frequency = 1372 Hz

Answer:

A) It requires extremely high pressure.

Explanation:

The reasons why we haven't been able to harness power from fusion is that its energy requirements are unbelievably, terribly high.

The correct statement is: "nuclear fusion requires extremely high pressure."

To find the correct statement among all the options, we need to know about nuclear fusion.

What is nuclear fusion?

How much pressure is required for nuclear fusion?

How much energy is released during nuclear fusion?

What is the comparison of energy that released in nuclear fusion and fission?

How does we get energy in the nuclear fusion reaction?

Thus, we conclude that option (A) is correct.

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The answer is (A.) The sail is pushing the wind back and slowing down the air. The wind is pushing the sail and the sail pushes the wind back and slows the air down.

As the boat is sailing, the wind will be faster than the boat. This fast wind is obstructed by the sail. That is, the fast wind gets slowed down by the sail because the sail pushes the wind backwards which slows down the wind. This will make the wind push the boat forward thereby accelerating the boat.

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Speed = (distance covered) / (time to cover the distance)

Speed = (400 ft) / (25 seconds)

Speed = 16 ft/sec

That's the car's speed.

We don't have enough information to state its velocity.

Answer:

36.m/s/s

Explanation:

Answer:

it is B

Explanation:

B

Statement B describes one way that nuclear fission differs from nuclear fusion in that nuclear fission can occur spontaneously.

The utilization of nuclear reactions to generate energy is known as a nuclear power. Nuclear fission, nuclear decay, and nuclear fusion processes are all sources of nuclear energy.

Nuclear power facilities currently produce the great bulk of the electricity generated by nuclear fission of uranium and plutonium.

Statement B describes one difference between nuclear fission and nuclear fusion in that nuclear fission can occur spontaneously.

Hence,option B is correct.

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Answer:

The first option- Sun shining through clouds

Explanation:

Answer:

Thus 1 Ampere is the current is defined as flow of 1 coulomb charge through a conductor in 1 second.

Explanation:

Hope it helps

Answer:

3V

Explanation:

From the question given above, we can see clearly that the resistors are arranged in parallel connection. Hence, the same voltage will pass through the resistors i.e

Total voltage = voltage of 3 Ω = voltage of 6 Ω

From the question given above,

The total voltage = 3 V

Therefore,

Voltage of 3 Ω = total voltage

Voltage of 3 Ω = 3V

Thus, option 3 gives the correct answer to the question.

Answer:

-7.5

Explanation:

edge 2021

Answer:

[tex]Vg=200mile/hr[/tex]

[tex]\theta=153 \textdegree[/tex]

Explanation:

From the question we are told that:

Plane airspeed [tex]v_p=190mil/h[/tex]

Plane direction [tex]\angle=150 \textdegree[/tex]

Wind current speed [tex]V_w=30mil/h[/tex]

Wind direction [tex]\angle=150 \textdegree[/tex]

Generally the vector form of the forces is mathematically given by

For plane

[tex]\angle Q_p=90-150 \textdegree[/tex]

[tex]V_p=170(cos60 \textdegree ,sin60 \textdegree)[/tex]

[tex]V_p=(85,-147.224)[/tex]

For wind

[tex]\angle Q_w=90-170 \textdegree[/tex]

[tex]V_w=30(cos-80 \textdegree ,sin-80 \textdegree)[/tex]

[tex]V_w=(5.2,-29.54)[/tex]

Generally the equation for resultant force is mathematically given by

[tex]v_r=V_a+V_w[/tex]

[tex]v_r=(85,-147.224)+(5.2,-29.54)[/tex]

[tex]v_r=(90.21,-176.76)[/tex]

[tex]v_r=198.45\angle -63[/tex]

Therefore ground speed

[tex]V_g=198.5miles/hr[/tex]

[tex]Vg=200mile/hr[/tex]

Direction

[tex]\theta=(90+63)=153 \textdegree[/tex]

[tex]\theta=153 \textdegree[/tex]

Answer:

Explanation:

Its resistor

Answer:

1. (a) The final velocity is 20 m/s

(b) The distance travelled is20 meters

2. The distance travelled by the train in the 30 seconds is 825 meters

3. The most correct option is;

(d) 53 km

4. The heat, developed by the electric iron is 15,000 joules

5. a) In the first network the resistance between A and B is 2 Ω

b) In the second network the resistance between A and B is 4Ω

c) In the third network the resistance between A and B is 6Ω

d) In the fourth network the resistance between A and B is 2Ω

Explanation:

1. (a) The parameters of the cheetahs motion are;

The initial motion (velocity) of the cheetah = 0 m/s (The cheetah starts from rest)

The acceleration of the cheetah, a = 2 m/s²

The duration of the acceleration of the cheetah, t = 10 seconds

The kinematic equation of the motion of uniform acceleration, of the cheetah can be written in the following form;

v = u + a·t

s = u·t + 1/2·a·t²

Where;

v = The final velocity

u = The initial velocity = 0 m/s

a = The acceleration of the cheetah = 2 m/s²

s = The distance traveled

∴ v = 0 + 2 × 10 = 20

The final velocity, v = 20 m/s

(b) From s = u·t + 1/2·a·t², we have;

s = 0 × 10 + 1/2 × 10 × 2² = 20

The distance travelled, s = 20 meters

2. The given details of the motion of the train are;

The initial velocity of the train, u = 20 m·s⁻¹

The acceleration of the train, a = 0.5 m·s⁻²

The duration of the train's acceleration, t = 30 seconds

Therefore, the distance travelled, 's', is given by; s = u·t + 1/2·a·t²

∴ s = 20 × 30 + (1/2) × 0.5 × 30² = 825

The distance travelled by the train in the 30 seconds, s = 825 meters

3. The given distance the truck covers with the average speed of 80 km/h, d₁ = 40 km

The distance the truck then covers with the average speed of 40 km/h, d₂ = 40 km

[tex]Average \ speed = \dfrac{Total \ distance}{Time}[/tex]

[tex]\therefore time, \, t = \dfrac{Total \ distance}{Average \ speed}[/tex]

The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(80 km·h) t₁ = 0.5 hour

The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(40 km·h) t₂ = 1 hour

The total time taken to cover both 40 km distances, t = t₁ + t₂

∴ The total time taken to cover both 40 km distances, t = (0.5 + 1) hour = 1.5 hours

The total distance covered at both speeds, d = d₁ + d₂

∴ d = 40 km + 40 km = 80 km

The average speed of the truck for the total distance, [tex]v_{average}[/tex] = d/t

∴ [tex]v_{average}[/tex] = 80 km/1.5 hours = 53.[tex]\overline 3[/tex] km/h ≈ 53 km/h

The average speed of the truck for the total distance, [tex]v_{average}[/tex] ≈ 53 km/h

The correct option is (d) 53 km

4. The heat, 'H', developed by the electric iron is given by the following formula;

H = I²·R·t

Where;

I = The current flowing in the electric iron = 5 A

R = The resistance of the iron = 20Ω

t = The time duration of the flow of the current = 30 s

∴ H = (5 A)² × 20 Ω × 30 s = 15,000 joules

The heat, developed by the electric iron, H = 15,000 joules

5. Let 'R' represent the resistance between A and B in each network

a) For the first network, we have;

1/R = 1/(2 + 2) + 1/(2 + 2) = 1/4 + 1/4 = 1/2

∴ R = 2 Ω

∴ The resistance between A and B is 2 Ω

b) For the second network, we have;

R = 1/(1/2 + 1/2) + 3 = 4

R = 4Ω

∴ The resistance between A and B is 4 Ω

c) For the third network, we have;

R = 2 + 1/(1/4 + 1/4) + 2 = 6

R = 6Ω

∴ The resistance between A and B is 6 Ω

d) For the fourth network, we have;

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

R = 2Ω

∴ The resistance between A and B is 2 Ω

The length of the string is 75 cm.

Centripetal acceleration is a characteristic of an object's motion along a circular path. Centripetal acceleration applies to any item travelling in a circle with an acceleration vector pointing in the direction of the circle's center.

Given that:  The centripetal acceleration of the ball is: a = 24.7 m/s^2.

constant speed of the ball is: v = 4.3m/s.

Let  the length of the string is l.

We know that:   The centripetal acceleration: a = v^2/l

l = v^2/a

= (4.3)^2/24.7

= 0.75 m.

Hence,  the length of the string is 0.75 m or 75 cm.

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Answer:

The speed of the student just before she lands, v₂ is approximately 8.225 m/s

Explanation:

The given parameters are;

The mass of the physic student, m = 43.0 kg

The height at which the student is standing, h = 12.0 m

The radius of the wheel, r = 0.300 m

The moment of inertia of the wheel, I = 9.60 kg·m²

The initial potential energy of the female student, P.E.₁ = m·g·h₁

Where;

m = 43.0 kg

g = The acceleration due to gravity ≈ 9.81 m/s²

h = 12.0 h

∴ P.E.₁ = 43 kg × 9.81 m/s² × 12.0 m = 5061.96 J

The kinetic rotational energy of the wheel and kinetic energy of the student supporting herself from the rope she grabs and steps off the roof, K₁, is given as follows;

[tex]K_1 = \dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex]

The initial kinetic energy, 1/2·m·v₁² and the initial kinetic rotational energy, 1/2·m·ω₁² are 0

∴ K₁ = 0 + 0 = 0

The final potential energy of the student when lands. P.E.₂ = m·g·h₂ = 0

Where;

h₂ = 0 m

The final kinetic energy, K₂, of the wheel and student is give as follows;

[tex]K_2 = \dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]

Where;

v₂ = The speed of the student just before she lands

ω₂ = The angular velocity of the wheel just before she lands

By the conservation of energy, we have;

P.E.₁ + K₁ = P.E.₂ + K₂

∴ m·g·h₁ + [tex]\dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex] = m·g·h₂ + [tex]\dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]

Where;

ω₂ = v₂/r

∴ 5061.96 J + 0 = 0 + [tex]\dfrac{1}{2} \times 43.0 \, kg \times v_{2}^2+\dfrac{1}{2} \times 9.60 \, kg\cdot m^2 \cdot \left (\dfrac{v_2}{0.300 \, m} }\right ) ^2[/tex]

5,061.96 J = 21.5 kg × v₂² + 53.[tex]\overline 3[/tex] kg × v₂² = 21.5 kg × v₂² + 160/3 kg × v₂²

v₂² = 5,061.96 J/(21.5 kg + 160/3 kg) ≈ 67.643118 m²/s²

v₂ ≈ √(67.643118 m²/s²) ≈ 8.22454363 m/s

The speed of the student just before she lands, v₂ ≈ 8.225 m/s.

Answer:

""gravity. the force that pulls on objects and causes acceleration if the objects are not balanced by an opposing force. speed. distance traveled per unit time. Newton's Second Law of Motion.""

Explanation:

Answer:

negative

Explanation:

positive charges attract negative charges and vice versa. and are possible to nullify