please help me with this

Answer:

120 m/s

Explanation:

acceleration = velocity/time

10m/s^2 = velocity / 12seconds

10*12 = velocity

120m/s = velocity

Answer:

18 000 m/ s

Explanation:

speed = wavelength * frequency

speed =  1.2  * 15 000 = 18 000 m/s

Problem 2

Answer: Choice D only

Explanation:

Let's go through the list of possible answers

The raising of window blinds is changing the amount of work done because work is easier by changing the direction of the force.

Work done refers to the product of component of a force in the direction of distance and the magnitude of this distance.

According to this question, a woman raises window blinds by pulling down on the cord.

The work done on the blind is made easier because load is relieved by changing the direction of the force.

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Answer:

[tex]\huge\boxed{\sf Work\ done = 4 kJ}[/tex]

Explanation:

Since work done is in the form of potential energy, we will use the formula of potential energy here.

We know that,

Where,

m = mass = 20 kg

g = acceleration due to gravity = 10 m/s²

h = vertical height = 20 m

So,

Work done = (20)(10)(20)

Work done = 4000 joules

Work done = 4 kJ

[tex]\rule[225]{225}{2}[/tex]

The magnitude of the angular acceleration of the magnetic disk is determined as 35 rad/s².

The angular acceleration of the disk is determined from the principle of conservation of angular momentum as follows;

τ = Iα

where;

α is angular acceleration

I is moment of inertia of the disk

I = 0.5MR²

I = 0.5 x 0.2 x 2²

I = 0.4 kgm²

τ = Iα

α = τ/I

α = (14)/(0.4)

α = 35 rad/s²

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From the calculation, Sheila’s velocity immediately after she is thrown from the bike is 5.7 m/s.

Momentum is the product of mass and velocity. We know that the momentum before collision is equal to the momentum after collision.

Hence;

Momentum before collision = 340 kg • m/s.

Momentum after collision = 60v

Thus;

340 kg • m/s = 60v  kg • m/s

v = 340 kg • m/s/60 Kg

v = 5.7 m/s

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Answer:

Displacement...

Explanation:

Displacement is a vector quantity as it have both magnitude and direction...

[tex]...[/tex]

a. displacement is the correct answer

Displacement is a vector quantity

Displacement is a vector quantity because it has both magnitude and direction.

The circuit change when a wire is added is, an open circuit occurs and makes all bulbs turn off.

A closed circuit is a type of circuit connection in which the wire connection is complete and current flow occurs, turning the light bulbs on in the process.

An open circuit is a type of circuit connection in which the wire connection is incomplete and current cannot flow, turning off the light bulbs.

Thus, the circuit change when the wire is added is, an open circuit occurs and makes all bulbs turn off.

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Answer:

f = 1.18 x 10¹¹ Hz

Explanation:

The equation used to find frequency is:

f = c / w

In this form, "f" represents the frequency (Hz), "c" represents the speed of light (3.0 x 10⁸ m/s), and "w" represents the wavelength (m).

Since you have been given the value of the constant (c) and wavelength, you can substitute these values into the equation to find frequency.

f = c / w                                                      <---- Formula

f = (3.0 x 10⁸ m/s) / w                                 <---- Plug 3.0 x 10⁸ in "c"

f = (3.0 x 10⁸ m/s) / (2.55 x 10⁻³ m)            <---- Plug 2.55 x 10⁻³ in "w"

f = 1.18 x 10¹¹ Hz                                         <---- Divide

(a) The force required to remove the sheet increases with increase in speed due to change in magnetic flux.

(b) The area in the magnetic field changes as the sheet is being put in between the poles. Thus, a force would be required to put the sheets.

When the sheet is pulled out, from the electromagnet there is change in magnetic flux given as follows;

Ф = BA

where;

emf = dФ/dt

F = qVB

Thus, the force required to remove the sheet increases with increase in speed due to change in magnetic flux.

Also, the area in the magnetic field changes as the sheet is being put in between the poles. Thus, a force would be required to put the sheets.

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Hello!

We can use the following equation for the potential difference between two parallel plates given an electric field and separation distance:
[tex]V = Ed[/tex]

V = Potential Difference (? V)
E = Electric field strength (100.0 N/C)

d = distance between places (0.02 m)

Plug in the values and solve.

[tex]V = (100)(0.02) = \boxed{2 V}[/tex]

The voltage across the resistor increases because extra electron gained by the LDR when the light is shone on it.

Increase in the voltage can occur due to some of the following reasons.

From Ohm's law voltage is directly proportional to current flowing in a circuit.

V ∝ I

The voltage across the resistor increases because extra electron gained by the LDR when the light is shone on it.

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The mass of a rollercoaster car moving at a velocity of 30 meters/second and has a momentum of 2.5 × 104 kilogram meters/second is 8.3 × 10²kg.

The mass of the roller coaster car can be calculated using the following formula:

P = m × v

Where;

m = 2.5 × 10⁴ ÷ 30

m = 8.3 × 10²kg

Therefore, the mass of a rollercoaster car moving at a velocity of 30 meters/second and has a momentum of 2.5 × 104 kilogram meters/second is 8.3 × 10²kg.

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Answer:

current

Explanation:

According to ohm’s law, resistance is equal to voltage divided by current.

Answer:

According to ohm’s law, resistance is equal to voltage divided by current.

Explanation:

R = resistance

V = voltage

I = current

R = V/I

hope this helps!! p.s. i really need brainliest :)

Answer:

c

Explanation:

wavelength shorter means energy is higher

the wavelength

radio waves>microwave>infrared rays>gamma rays

Answer: C. Be more dense and flow under warm air.

Explanation:

think of a supermarket selling dairy products and when you open the fridge to get the milk, outside the supermarket is hot and inside the fridge is cold ice.

Answer:

Magnetic field lines are a visual tool used to represent magnetic fields.meaning you cant really see them with out the tool witch magnetic force on a north and south

Hope This Helped

In the freezing physical change, when 210.0 g of water a 0 degrees freezes into ice, it gives off 71.0 kJ of heat.

It is a physical change in which liquids give off heat to form solids.

We have 210.0 g of water at 0°C. We can calculate the amount of heat given off when it freezes into ice using the following expression.

Q = ΔH°fus × m

Q = 0.334 kJ/g × 210.0 g = 70.1 kJ

where,

In the freezing physical change, when 210.0 g of water a 0 degrees freezes into ice, it gives off 71.0 kJ of heat.

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Answer:

0.56 Watt

Explanation:

Work done = 8 kJ = 8000J

Time = 4 hours = 4*60*60s = 14400sec

Power = ?

Formula of Power is,

Power = Work done / Time

Power = 8000/14400

Power = 0.56 Watt

Hence, Power of person is 0.56Watt.

An object's acceleration if it is moving and comes to a stop in 5 s will be  8 m/s².

Acceleration is defined as the rate change of velocity with time.

acceleration a = (Δv) / (Δt)

An object is moving with initial velocity u = 40 m/s and it comes to stop, then its final velocity  v= 0 m/s.

Time taken for the change in speed t=5s.

The acceleration is given by

a = (40 -0)/ 5

a = 8 m/s²

Thus, the object's acceleration is  8 m/s².

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The amount of heat energy that must still be removed by the cooling system is 1300 kJ.

The total energy before and after a transformation must be equal.

Based on this principle, the heat energy that must still be removed by the cooling system is calculated as follows;

Input heat energy = out put heat energy

E = h + w

2000 kJ = h + 700 kJ

1300 kJ = h

Thus, the amount of heat energy that must still be removed by the cooling system is 1300 kJ.

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The direction of the angular velocity of the minute hand of a wall-clock is perpendicular to the wall and directed inwards.

The passenger slides away from the centre of the curve.

The angle θ which a cyclist should make with the vertical while taking a circular turn of radius r with velocity v given by

tan θ = v^2/rg

Sharper the curve, smaller is the radius and greater is the value of 0.

Answer:

230.4kg

Explanation:

volume of the room = l× b×h

volume= 8×6×4

volume=192m3

density= mass/volume

hence mass= density × volume

mass= 1.2kgm-3 × 192m3

mass= 230.4kg

Answer:

48MJ

Explanation:

Formula :

Work done = Power × time

============================================================

Given :

⇒ Power = 80,000 W = 80kW

⇒ Time = 60s

=============================================================

Solving :

⇒ Work done = 80kW × 60s

⇒ Work done = 4800kJ

⇒ Work done = 48MJ (megajoule)

Answer:

Explanation: RADIUS OF EARTH = 6400X1000m =

ACC DUE GRAVITY ABOVE SURFACE OF EARTH = g' =2.45 m/s^2

ACC DUE GRAVITY ON SURFACE OF EARTH =g= 9.8 m/s^2

A/C TO FORmULA

g'/g=1-2h/Re

g'/g +2h/Re = 1

2h/Re =1- g'/g

2h= (1- g'/g)Re

2h=(1-2.45 /9.8)

6400X1000

2h = (0.75)6400X1000

2h = 4800000

h= 2400000

m

The time delay between the arrival of the two pulses at the ceiling is 2.33 ms.

Any object of mass is attracted towards another by point where whole mass is supposed to be concentrated is called center of gravity.

A 1750 N irregular beam is hanging horizontally by its ends from the ceiling by two vertical wires (A and B), each 1.25 m long and weighing 0.290 N.

The center of gravity of this beam is one-third of the way along the beam from the end where wire A is attached.

Taking moments about one end, to find the tension at other end.

Tb X L = WxL/3

here, W is the weight, L is the length of wire and Tb is the tension at point B.

So, Tb = W/3

and
Tb - Ta = W

here, Ta is the tension in end A.

Substitute the values, we get

Tb = 583.33N and Ta = 1166.66N

Velocity of end A, Va = (1166.66 x1.25 x 9.81/0.290 )^(1/2)

Va = 222 m/s

Velocity of end B, Vb = (583.33 x1.25 x 9.81/0.290 )^(1/2)

Va = 157 m/s

Time delay t is related with the velocities as

t = L/Vb - L/Va

Substitute the values, we get

t= 0.00233 s

t = 2.33 ms

Thus, time delay between the arrival of the two pulses at the ceiling is 2.33 ms.

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The actual question should be did the sound waves escape room?

Yes they can escape the room

Answer:

55 kg

Explanation:

Formula :

Force = mass × acceleration

=========================================================

Given :

⇒ Force = 220 N

⇒ acceleration = 4 m/s²

===========================================================

Solving :

⇒ 220 N = mass × 4 m/s²

⇒ mass = 220/4

⇒ mass = 55 kg

The statement that is true regarding the objects is that object 1 had faster-moving particles, which is option 2. Details about matter can be found below.

Matter can be defined as any particle that has weight and occupies space.

Certain particles are present in the different states of matter. According to this question, when object 1 came into contact with object 2, object 2 got warmer.

This suggests that the particles in the object 1 is moving faster due to an increase in temperature.

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Answer: b

Explanation: i took the quiz