A magician performs in a room with a ceiling, which is 2. 70 m above his hands. He throws a ball upwards such that it reaches the ceiling with zero speed. Calculate the initial speed of the ball and the time it takes for it to reach the ceiling.

The average speed of a plane taking off on the runway of an airport and accelerates at 3.5 m/s² is 26.25m/s.

Average speed is the rate that is a quantity divided by the time taken to get that quantity. The SI unit of speed is meters per second (m/s).

The acceleration of a moving body is the change of velocity with respect to time (can include deceleration or changing direction).

Acceleration = change in speed ÷ time

According to this question, a plane taking off on the runway of an airport accelerates at 3.5 m/s² from rest for 7.5s. The average speed is calculated as follows:

3.5 = v/7.5

v = 26.25m/s

Therefore, 26.25m/s is the average speed of the plane.

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Answer:

0

Explanation:

Moving east at constant velocity then a=0

Difference is that science is a particular discipline or branch of learning, especially one dealing with measurable or systematic principles rather than intuition or natural ability or science can be scion while physics is the branch of science concerned with the study of properties and interactions of space, time etc

Key words

\(\\ \rm\hookrightarrow Q_{initial}=Q_{Final}\)

\(\\ \rm\hookrightarrow m1c1\Delta T=m2c2\Delta T\)

\(\\ \rm\hookrightarrow 25c1=(200+10)(1)\)

\(\\ \rm\hookrightarrow 25c1=210\)

\(\\ \rm\hookrightarrow C1=210/25\)

\(\\ \rm\hookrightarrow C1=8.4cal/g°C\)

The correct answer is 8.4 J⋅kg−1⋅K−1

Explanation :

We know that

Qi = Qf  

Therefore ,m1c1 ΔT = m2c2ΔT

Where m1 is 25g and m2 is 200g

so , 25c1 = (200+10)(22-2)

      25c1 = 420

Therefore , c1 = 210/25

c1 = 16.8J⋅kg−1⋅K−1

Hence the specific heat of metal is 16.8 J⋅kg−1⋅K−1

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Answer:

Explanation:

all

"Energy" is the ability to do work.

"Work" is the process of using energy.

The statement "They have a positive charge and are present in the nucleus of an atom along with the neutrons" correctly describes protons.

Protons are small particles that make up the nucleus of an atom. They carry a positive charge and have a mass of approximately 1 atomic mass unit. The number of protons within an atom's nucleus defines its atomic number and thus its identity as an element.

For instance, carbon atoms have 6 protons, and oxygen atoms have 8 protons. Protons are vital building blocks of all atoms and play a significant role in the chemical behavior and reactions of elements.

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In an electric field, a positive charge experiences a force in the direction opposite to the electric field lines. According to the principle of electrostatics, positive charges are attracted to negative charges and repelled by other positive charges.

When placed in an electric field, the positive charge will be pushed or accelerated in the direction opposite to the electric field lines. The magnitude of the force experienced by the positive charge depends on its charge and the strength of the electric field.

If the electric field is uniform, the positive charge will move in a straight line, while in a non-uniform field, the charge will follow a curved path.

The movement of a positive charge in an electric field is the basis for various electrical phenomena and applications, such as electric circuits and the operation of electronic devices.

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Answer:

14m/s

Explanation:

Given data

M1=45kg

U1=2m/s

M2=90kg

U2=7m/s

V1=?

V2=1m/s

Applying the expression for elastic collision

M1U1+M2U2=M1V1+M2V2

Substitute

45*2+90*7=45*V1+90*1

90+630=45V1+90

720-90=45V1

630=45V1

Divide both sides by 46

V1=630/45

V1=7.5m/s

Hence Bruce's speed is 14m/s

Answer:

b,d,f

Explanation:

Answer:

v = 46.67 km/h

Explanation:

We will use the following formula throughout this numerical:

s = vt

where,

s = distance covered

v = speed

t =  time taken

FOR FIRST 30 km:

s = 30 km

v = 30 km/h

t = t₃₀ = ?

Therefore,

30 km = (30 km/h)(t₃₀)

t₃₀ = (30 km)/(30 km/h)

t₃₀ = 1 h

FOR TOTAL 100 km:

s = 100 km

v = 40 km/h (Average Speed)

t = total time = ?

Therefore,

100 km = (40 km/h)(t)

t = (100 km)/(40 km/h)

t = 2.5 h

FOR LAST 70 km:

s = 70 km

t₇₀ = t - t₃₀ = 2.5 h - 1 h = 1.5 h

v = v₇₀ = ?

Therefore,

70 km = v(1.5 h)

v = 70 km/1.5 h

v = 46.67 km/h

Answer:

A

Explanation:

Answer: 55 degrees celsius

Explanation:

The measured temperature of the mixture of water was 50°C.

When two physical systems are connected by a heat-permeable path, they are in thermal equilibrium if there is no net flow of thermal energy between them.

The zeroth law of thermodynamics governs thermal equilibrium. A system is said to be in thermal equilibrium with itself if the temperature within it is uniform and constant over time.

Initial temperature of 100 mL of water is 20°C

and Initial temperature of 100 mL of water is 80°C

Let at thermal equilibrium, temperature of the mixture is t° C.

Hence, at thermal equilibrium,

100 mL × ρ × ( t - 20°C) × s = 100 mL × ρ × ( 80°C -t) × s

t - 20° C = 80°C -t

2t = 100°C

t = 50°C

Hence, the measured temperature of the mixture of water was 50°C.

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Explanation:

Given that,

Initial position, h₀ = 50 m

A rock is tossed straight up into the air with a velocity of 20.0m/s

(a) When the rock reaches its maximum height, its final velocity, v = 0. Using equation of kinematics as follows :

v=u+at

here, a = -g

\(t=\dfrac{u}{g}\\\\t=\dfrac{20\ m/s}{10\ m/s^2}\\\\t=2\ s\)

(b) Let h is the maximum height reached by the toss. It can be given by :

\(h=h_0+ut-\dfrac{1}{2}gt^2\\\\h=50+20\times 2-\dfrac{1}{2}\times 10\times 2^2\\\\h=70\ m\)

(c) Let T is the time it takes the rock to reach the ground. It is equal to the sum of time reaches to its maximum height and the remaining time. It can be calculated as follows :

\(T=t+\sqrt{\dfrac{2h}{g}}\)

Putting all the values,

\(T=2+\sqrt{\dfrac{2\times 70}{10}}\\\\T=5.74\ s\)

(d) Let v is the velocity of the rock as it hits the ground. It can be calculated as follows :

v = u - gt

\(v = 20 - (10)(5.74)\\\\v=-37.4\ m/s\)

Negative sign shows it comes in downward direction.

Answer:

the answers, the correct one is C,   v₀ₓ = vₓ = 3.91 m / s

Explanation:

This is a projectile launching exercise, in this case they indicate that when leaving the cliff it goes horizontally, therefore the initial vertical speed is zero, let's find the time to reach the base

        y = y₀ + \(v_{oy}\) t - ½ g t²

at the base the height is zero (y = 0 m)

        0 = y₀ + 0 - ½ g t²

         t = √ (2y₀ / g)

we calculate

        t = √ (2 200 / 9.8)

        t = 6.389 s

with this time we calculate the horizontal speed

        v₀ₓ = x / t

        v₀ₓx = 25 / 6,389

        v₀ₓ = vₓ = 3.91 m / s

When checking the answers, the correct one is C

Answer:

bc we play when we are bored and some people use it as a tradition to play on thanksgiving

The energy added to the car's battery is 76 kJ when it comes to a complete stop

The question can be answered by using the following formula to calculate energy:

Ek = (1/2)mv²

The kinetic energy (EK) of the car is 200 kJ.

We will use the same formula to calculate the initial velocity of the car:

Ek = (1/2)mv²

200000 = (1/2)m × v²

v² = 400000/mv = √(400000/m)

The formula for the energy added to the battery is given by the following formula:

AE = -εEk

where:ε is the efficiency of regenerative brakingε = -0.38

The negative sign indicates that energy is being extracted from the car's kinetic energy and put into the battery. The efficiency of regenerative braking is given as a decimal value, so we can plug the values into the formula:

AE = -(-0.38) × 200000

AE = 76000J

AE = 76 kJ

Therefore, the energy added to the car's battery is 76 kJ when it comes to a complete stop (within three significant digits).

This implies that 38% of the car's kinetic energy is captured and stored in the battery.

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Answer:

The resultant momentum is 12.97 kg.m/s. Choice: c

Explanation:

Momentum

The momentum is a vector that measures the quantity of motion that an object has. It's also known by the term "mass in motion".

As a vector, it can be expressed by its rectangular components:

\(\vec p = p_x\mathbf{i}+p_y\mathbf{j}\)

The magnitude of the momentum is:

\(\mid \mid \vec p \mid \mid =\sqrt{p_x^2+p_y^2}\)

The object described has an x-component of:

px=8.5 Kg.m/s

And a y-component of:

py=9.8 Kg.m/s

Thus, the magnitude of the momentum is:

\(\mid \mid \vec p \mid \mid =\sqrt{8.5^2+9.8^2}\)

\(\mid \mid \vec p \mid \mid =\sqrt{72.25+96.04}\)

\(\mid \mid \vec p \mid \mid =\sqrt{168.29}\)

\(\mid \mid \vec p \mid \mid =12.97\)

The resultant momentum is 12.97 kg.m/s. Choice: c

The average force exerted by the club on the ball is 838,400 N. Force can be characterized by its magnitude, direction, and point of application.

It can be a push or pull, and it can cause an object to start moving, stop moving, or change its direction of motion.

Force is indeed a physical factor that alters or has the potential to alter an object's state at rest or motion as well as its shape. Newton is the SI unit of force.

Finally, the average force exerted by the club on the ball is:

F = I / t = (1676.8 N·s) / (0.0020 s) = 838,400 N

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The force that must be applied on the brakes to hold the aircraft stationary is 84.51 kN (approx).

The force that must be applied on the brakes to hold the aircraft stationary is 84.51 kN.

Step 1:We can determine the exhaust gas temperature using the formulaT4 = T3 + (qin / (cp * m_dot)).Where,T3 = 1191.7 K (Given)qin = heating value of fuel × mass flow rate of fuel = 42,700 × 0.2 = 8,540 kJ/kgcp = specific heat at constant pressure = 1.005 kJ/kg.Km_dot = mass flow rate of air + mass flow rate of fuel = 10 + 0.2 = 10.2 kg/s

Putting all the values,T4 = 1191.7 + (8,540 / (1.005 * 10.2)) = 1191.7 + 84.85 = 1276.55 K

Step 2:The static thrust produced by the engine can be found out by the formula:

F = m_dot * (V2 - V1) + A2 * (P2 - P1)

Where,m_dot = mass flow rate of airA2 = area of the exhaust nozzleV1 = velocity of air at the engine inletV2 = velocity of air at the engine exitP1 = pressure of air at the engine inletP2 = pressure of air at the engine exitWe can use the simplified form of the above formula, which neglects the increase in the kinetic energy of the air in the combustor, the increase in the potential energy of the air from the inlet to the exhaust, and the change in the kinetic energy of the air from the inlet to the exhaust.F = m_dot * (Ve - V1) + Ae * (Pe - P1)

Where,Ve = velocity of air at the engine exitAe = area of the exhaust nozzlePe = pressure of air at the engine exitWe can calculate the value of Ve using the formula:Ve = sqrt(2 * cp * T4 * (1 - (P2 / P1)^((γ - 1) / γ))))Where,γ = ratio of specific heats = 1.4Putting all the values,Ve = sqrt(2 * 1.005 * 1276.55 * (1 - (1 / 12)^0.4))) = 724.23 m/sNow, we can calculate the static thrust,F = m_dot * (Ve - V1) + Ae * (Pe - P1)= 10.2 * (724.23 - 0) + (0.785 * (0.25)^2 * (12 * 10^3 - 95) * 10^3)= 74,044.47 N

Step 3:The force that must be applied on the brakes to hold the aircraft stationary is equal and opposite to the static thrust, that is, 74,044.47 N.

The value in kN will be: 74.04447/1000 = 74.04 kN.

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Answer:

the awnser is c The salinity of ocean water decreases and the temperature of ocean water increases as the depth increases.

Answer:

560

Explanation:

56*10=560

hope this helps :3

if it did pls mark brainliest

Answer: 560 cats

Explanation: 56x10 = 560.

Answer:

B) is the answer

Explanation:

A) is 25 N

B) is 36N

C) is 30N

D)15N

The expression for the number of electrons Ne in the speck of dust in terms of the charge of an electron, \(q_{e}\) , and other variables is

Ne= Np + Q/\(q_{e}\)

The outside of the nucleus is surrounded by negatively charged electrons in orbit. It can be challenging for scientists to observe them because they spin so quickly. They are the smallest particles in an atom and are drawn to the protons positive charges; one proton can hold 2000 of them.

\(N_{p}\) = 1.75 x 10¹⁷ protons.

Q = -37 nc

Part a -  Since the net charge on a speck of dust is negative.

So, the number of excess electrons on it will be = Q/\(q_{e}\)

Thus, the total number of electrons on the speck of dust will be:

Ne= Np + Q/\(q_{e}\)

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Complete question is

Answer  Rivers are not considered landforms

Explanation:

Answer:

The answer is D because when the faults move that is the tectonic plates moving. So earth quakes will be forming when the fault moves.

Explanation:

Teniendo en cuenta la definición de aleación, el latón es una aleación de cobre y zinc, mientras el bronce es una aleación de cobre y estaño.

Una aleación se define como una mezcla homogénea de un metal con uno o más elementos diferentes, tanto metálicos como no metálicos.

Las aleaciones generalmente se consideran mezclas homogéneas, porque los átomos de los componentes combinados no producen reacciones químicas que formen un nuevo compuesto químico.

Los elementos de la aleación generalmente se dividen en dos categorías, el metal base y los elementos de aleación. El elemento base es el que se encuentra en mayor cantidad en la aleación, mientras que los elementos de aleación son los que se encuentran en menor cantidad.

Finalmente, el latón es una aleación de cobre y zinc, mientras el bronce es una aleación de cobre y estaño.

Aprende más:

Speed of the Cylinder after it has descended = 3.675m/s

A fundamental principle of physics and chemistry stating that despite internal changes, the overall energy of an isolated system remains constant. The first law of thermodynamics, which is most usually phrased as "energy cannot be created or destroyed," is based on this fundamental idea.

According to the given information

Inertia of gear \($A=10^*(0.125)^{\wedge} 2=0.15625$\)

Inertia of gear \($B=30^*(0.15)^{\wedge} 2=0.675$\)

Let the speed of cylinder be \($\mathrm{v}$\)

angular speed of block \($\mathrm{C}=\mathrm{v} / 0.1 \mathrm{~m} / \mathrm{sec}=10 \mathrm{v}$\)

angular speed of \($\mathrm{A}=(\mathrm{v} / 0.1) * 0.2 / 0.15=13.33 \mathrm{v}$\)

Conserving energy

\($50 * 9.81^* 2=0.5\left(50^* \mathrm{v}^{\wedge} 2+0.15625^*(13.3 \mathrm{v})^{\wedge} 2+0.675^*(10 \mathrm{v})^{\wedge} 2\right)$\)

So,

\($50 * 9.81^* 2=0.5\left(50^* \mathrm{v}^{\wedge} 2+0.15625^*(13.3 \mathrm{v})^{\wedge} 2+0.675^*(10 \mathrm{v})^{\wedge} 2\right)$\)

So,

Speed of the Cylinder after it has descended = 3.675m/s

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