(1) A string of constant thickness and length I cm is stretched by a force of T Newton. A
tuning fork stamped 256 Hz sets the string vibrating at its fundamental frequency.
Find the frequency of the string when:
(i) Its length is doubled and the tension constant;
(ii) the tension is doubled and the length constant.
2) State the effect of increase in the tension on a wire on its frequency.

Answer:

A ball rolls off the table and free falls to the ground. Which statement accurately describes its acceleration? Its acceleration is downward but remains a constant value as it falls.

Answer:

hope fully it help s

Answer:

Acceleration is the rate of change of velocity with time.its system international unit is meters per second square.

I hope this helps

Answer:

Velocity is the speed of something given in a direction. the SI unit of velocity is metre per second or m/s.

Answer:

A) I_laser = 70.74 W/m²

B) I_bulb = 1.989 W/m²

C) it is not advisable to look at the laser beam directly.

Explanation:

We are given;

Power; P = 0.50 mW = 0.5 × 10^(-3) W

Diameter; d = 3 mm = 0.003 m

Radius; r = d/2 = 0.003/2 = 0.0015 m

A) Area of beam; A = πr²

A = 0.0015²π

Now, formula for average intensity is;

I = P/A

I = (0.5 × 10^(-3))/0.0015²π

I = 70.74 W/m²

B) We are told to find the intensity of a lightbulb producing 100-W.

Thus, P = 100 W

A light bulb is spherical in shape. Thus;

Area; A = 4πr²

We are told it's 2 m away.

Thus; r = 2 m

A = 4π(2)²

A = 16π

Thus, I = P/A = 100/16π

I = 1.989 W/m²

C) The intensity of the laser beam is far greater than that of the light bulb. Thus, it is not advisable to look at the laser beam directly.

Answer:

The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N

Explanation:

The details of the given masses having gravitational attractive force between them are;

m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m

The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;

[tex]F =G \cdot \dfrac{m_{1} \cdot m_{2}}{r^{2}}[/tex]

Where;

F = The gravitational force between m₁ and m₂

G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²

r₂ = 0.1 m + 0.15 m = 0.25 m

Therefore, we have;

[tex]F = 6.67430 \times 10^{-11} \ N \cdot m^2/kg \times \dfrac{20 \ kg\times 50 \ kg}{(0.1 \ m+ 0.15 \ m)^{2}} \approx 1.06789 \times 10^{-6} \ N[/tex]

The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N

Answer:

option C

Explanation:

Final velocity of the object is 114 m / s. Hence, final velocity of the object is 114 m / s.

We know

[tex]\boxed{\sf W=Fscos\theta}[/tex]

[tex]\\ \sf\longmapsto W=25(20)cos30°[/tex]

[tex]\\ \sf\longmapsto W=500\times \dfrac{\sqrt{3}}{2}[/tex]

[tex]\\ \sf\longmapsto W=250\sqrt{3}[/tex]

[tex]\\ \sf\longmapsto W=250(1.73)[/tex]

[tex]\\ \sf\longmapsto W\approx 430J[/tex]

Option a) 430 J work done he do after walking 20.0 m.

Work, in physics, is a measure of energy transfer that happens when an object exists moved over a distance by an external force at least part of which exists involved in the direction of the displacement.

Displacement exists as the distance moved in a straight line, in a provided direction, from the starting point. Displacement exists as a vector quantity as it includes size and direction.

An angle stands the figure formed by two rays, named the sides of the angle, sharing a standard endpoint, named the vertex of the angle.

⇒[tex]W=Fcos\theta[/tex]

⇒[tex]W=25(20)cos 30^{0}[/tex]

Then,

⇒[tex]W=50*\sqrt{3} /2[/tex]

⇒[tex]W=250\sqrt{3}[/tex]

Hence,

⇒[tex]W=250(1.73)[/tex]

[tex]W[/tex] approximately 430J.

Hence, Option a) 430 J work done he do after walking 20.0 m.

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The vaccine ofcourse. They helped in making the vaccine.

Answer:

Be serious or else CEO of brainly will kick you out

Answer:

contains many individual light detectors, each with its own lens

Explanation:

The compound eye is found mainly in insects and crustaceans, it is composed of individual receptor units, each with its focus, sensing nerve; each one gives a small image of the environment, so the image is mosaic type, not a complete integral image of the environment.

When reviewing the different statements, the correct one is

contains many individual light detectors, each with its own lens

Answer:

The total heat required to melt the ice is approximately 3.473 MJ

Explanation:

The given parameters for the layer of ice are;

The thickness of the layer of ice, t = 0.80 cm = 0.008 m

The area of the wind shield, A = 1.4 m²

The initial temperature of the ice, T₁ = -2.0 °C = 271.15 K

The density of the ice, ρ = 917 kg/m

The temperature at which ice melts, T₂ = 0 °C = 273.15 K

We have;

The mass of the ice, m = ρ × t × A

∴ m = 917 kg/m³ × 0.008 m × 1.4 m² = 10.2704 kg

The specific heat capacity of ice, c = 2,090 J/(kg·K)

∴ The equation for the heat capacity of the ice to melt, is given as follows;

ΔQ = m·c·ΔT

Where;

ΔT = T₂ - T₁

∴ ΔT = T₂ - T₁ = 273.15 K - 271.15 K = 2 K

ΔQ = 10.2704 kg × 2,090 J/(kg·K) × 2 K = 42.930272 kJ

The latent heat to melt the ice, Q = The latent heat of fusion of ice, L × Mass of ice, m

The latent heat of fusion of ice, L = 334 kJ/kg

∴ Q = 334 kJ/kg × 10.2704 kg = 3,430.3136 kJ

The total heat required to melt the ice, H = ΔQ + Q

∴ H = 42.930272 kJ + 3,430.3136 kJ = 3,473.243872 kJ ≈ 3.473 MJ.

Answer:

Kepler's laws apply: First Law: Planetary orbits are elliptical with the sun at a focus. Second Law: The radius vector from the sun to a planet sweeps equal areas in equal times. Third Law: The ratio of the square of the period of revolution and the cube of the ellipse semimajor axis is the same for all planets.

Answer:

EFFECTS Adverse reactions to hypnosis are rare, but may include: Headache. Drowsiness. Dizziness

Answer:

most evaporation and precipitation in the water cycle occus over the ocean

The option Most evaporation and precipitation in the water cycle occur over the ocean. is the correct answer

Answer:

250N

Explanation:

According to newton second law,

\sumF = ma

Fm - Ff = ma

Since the velocity is constant, a = 0m/s

Frictional force Ff = 250N

Substitute

Fm - 250 = m(0)

Fm - 250 = 0

Fm = 250N

Hence the force to keep the box sliding at constant speed is 250N

Answer:

Explanation:

F = ma, so filling in:

15000 = 30000a and

a = .50 m/s/s

The acceleration of a train is 0.50 [tex]m/s^{2}[/tex].

Acceleration is the rate of change of the velocity of an object with respect to time.

F = ma

a = F/m

a = 15000/30000

a = 0.50 [tex]m/s^{2}[/tex]

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Explanation:

B. Doubling the heat flow into the engine while halving the work done

hope this helps you

have a nice day

Answer:

The momentum makes it worse.

Explanation:

The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.

Answer:

Jet stream would be displaced southwards causing heavy rain and flooding.

Explanation:

The other options of the question were A) Jet stream would be displaced northwards causing drought. B) Jet stream would be displaced southwards causing drought. D) Jet stream would be displaced northwards causing heavy rain and flooding,

The statement that is a likely impact of stronger than normal trade winds in the Pacific Northwest to the United States is "Jet stream would be displaced southwards causing heavy rain and flooding."

We are talking about climate or weather terminology. In this case, we are referring to the "El Niño" (the Children) effect. Its presence affects the weather in North America. This phenomenon combines with the "La Niña) effect and it presents itself every two to seven years, ad they last from 8 to 12 months, affecting the weather conditions of the region.

Answer:

jet stream should be displaced southwards which causes heavy rainfall and flood.

Answer:

a) ii

b) i

c)iii

d)iii

e) i

f)iii

Explanation:

i hope this will help

Answer:

the answer of b is N and d is mol

Answer:

h = 2.78 m

Explanation:

Potential Energy(PE)

Mass(m)

Gravity(g) which is approximately equal to 10.

Height (h)

PE = mgh

41772.5 = 1500 * 10 * h

41772.5 = 15000h

h = 41772.5/15000

h = 2.78 m

The small ball will transfer its momentum to the heavier ball. Since the momentum gets conserved. The velocity will depend upon the mass of the balls.

According to the law of conservation of momentum. The momentum of the body before the collision is always equal to the momentum of the body after the collision.

The momentum of the body is given by the product of the mass and velocity of the body.

According to the law of conservation of momentum

Momentum before collision =Momentum after collision

Hence the small ball will transfer its momentum to the heavier ball.

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Answer:

Explanation:

The form of Newton's 2nd Law that we use for this is:

F - f = ma where F is the Force pulling the mass down the ramp forward, f is the friction trying to keep it from moving forward, m is the mass and a is the acceleration (and our unknown).

We know mass and we can find f, but we don't have F. But we can solve for that by rewriting our main equation to reflect F:

[tex]wsin\theta-\mu F_n=ma[/tex] That's everything we need.

w is weight: 6.0(9.8). Filling in:

6.0(9.8)sin20 - .15(6.0)(9.8) = 6.0a and

2.0 × 10¹ - 8.8 = 6.0a and

11 = 6.0a so

a = 1.8 m/s/s

From the description of the question, the acceleration is 1.95 ms-2.

The term friction is defined a the force that seeks to prevent the movement of a surface on another.

Now we know that;

ma =mgsinθ -  ukmgcosθ

ma =( 6 * 9.8 * sin 20) - ( 0.15 * 6 * 9.8 * cos 20)

a =  ( 6 * 9.8 * sin 20) - ( 0.15 * 6 * 9.8 * cos 20) /6

a = 20 - 8.29/6

a = 1.95 ms-2

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Answer:

The force is 3305.6 N.

Explanation:

Final velocity, v = 0

time, t = 2.25 ms

initial velocity, u = 4.25 m/s

mass, m = 1.75 kg

Let the acceleration is a.

Use first equation of motion.

v = u + a t

0 = 4.25 + a x 0.00225

a = - 1888.9 m/s^2

The force is

F = ma

F = 1.75 x 1888.9

F = 3305.6 N

Answer:

  an object sliding down hill

Explanation:

On a slope, the force applied is due to gravity. Its direction is straight down. If the object is sliding down the hill, its displacement is at an angle to the applied force. The angle of displacement will depend on the steepness of the hill.

Answer: 25 m/s

Explanation:

1. rearrange equation p = mv to find v

2. v = p/m - then convert 800 g into kg (= 0.8 kg)

3. plug in p and m - v = 20 / 0.8 = 25 m/s

Answer:

V= 25m/s

Explanation:

Mass=800g

Momentum=20kgm/s

V= ?

Convert 800g to kg

800/1000 = 0.8kg

Momentum=mass× Velocity

Momentum/Mass = Velocity

20/0.8 =25m/s

Gamma rays

used in radiotherapy