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Ek = 1/2 mv^2

9 × 10^4 = 1/2 × 800 × v^2

9 × 10^4/400 = 400 v^2 / 400

9 × 10^4/400 = v^2

√225 = v

15 ms⁻¹ = v

That's the only way I know how to work it out

I think in this case velocity and speed would be considered the same because me

s = d/t and v=d/t

one is distance travelled and the other is displacement of a body

Answer: the gravitational attraction on the Moon is much less than it is here on Earth, and a person weighs less on the Moon.

Explanation:

Answer:

[tex]\boxed {\boxed {\sf 4 \ Newtons}}}[/tex]

Explanation:

Work is energy transferred when an object is moved. It is the product of force and distance.

[tex]W= F*d[/tex]

John did 3.2 Joules of work or 3.2 Newton meters of work (the units are equivalent). The window shade was lowered a distance of 0.8 meters.

Substitute the values into the formula.

[tex]3.2 \ N *m = F * 0.8 \ m[/tex]

We are solving for the force, so we must isolate the variable F. It is being multiplied by 0.8 meters. The inverse operation of multiplication is division, so divide both sides of the equation by 0.8 m.

[tex]\frac {3.2 \ N*m}{0.8 \ m}= \frac{ F* 0.8 \ m}{0.8 \ m}[/tex]

The units of meters cancel.

[tex]\frac {3.2 \ N}{0.8 }=F[/tex]

[tex]4 \ N = F[/tex]

John must exert 4 Newtons of force.

Answer:    75n,a * (12m)

Explanation I'm trying to understand the question but this is what i got.

Happy Holidays!

We can use the following equation to calculate work done on an object.

W = F · d

Work (J) = Force (N) · displacement (m)

Plug in the given values into the equation:

W = 75 · 12 = 900 J

Photovoltaic panels are used to produce alternating current using sunlight. It uses solar cells which are photoactive and produce a photoelectric effect and thereby a potential is created.

When photons from the light energy is hit on a metallic surface the photon collides with the electrons of the metals and electrons are ejected from the metal surface. This phenomenon is called photoelectric effect.

In a solar photovoltaic panel, photovoltaic cells layers of semi-conducting materials, such as silicon, are sandwiched photovoltaic cells. When photons from sunshine strike each layer, its unique electronic properties energise and produce an electric field.

The current required to generate electricity is produced through what is known as the photoelectric effect. Electricity produced by solar panels is in the direct current form. This is then transformed into an alternating current by passing via an inverter.

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Answer:

Explanation:

The kinetic energy of an object can be found by using the formula

[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]

m is the mass in kg

v is the velocity in m/s

From the question

m = 1500 kg

v = 35 m/s

We have

[tex]k = \frac{1}{2} \times 1500 \times {35}^{2} \\ = 750 \times 1225 \\ = 918750[/tex]

We have the final answer as

Hope this helps you

From Newton's second law of motion, the average force on the ball by the racket is 98 Newtons. The correct answer is option C

Given that a 0.07 kg tennis ball, initially at rest, leaves a racket with a speed of 56 m/s. And the time for contact with the racket is 0.04 s, that is,

mass m = 0.07 kg

velocity v = 56 m/s

time t = 0.04 s

force f = ?

To calculate the average force on the ball by the racket, let us apply Newton's second law of motion.

Impulse = change in momentum

ft = mv

Substitute all the parameters into the equation above

0.04f = 0.07 x 56

make f the subject of the formula

f = 3.92 / 0.04

f = 98 N

Therefore, the average force on the ball by the racket is 98 Newtons. The correct answer is option C

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The average force on the ball by the racket is 98 N. The correct option is the third option - 98 N

From the question, we are to determine the average force on the ball by the racket.

From the formula,

[tex]F = \frac{mv}{t}[/tex]

Where F is the force

m is the mass

v is the velocity

and t is the time

From the given information

m = 0.07 kg

v = 56 m/s

t = 0.04 s

Putting the parameters into the formula,

we get

[tex]F = \frac{0.07 \times 56}{0.04}[/tex]

[tex]F = \frac{3.92}{0.04}[/tex]

F = 98 N

Hence, the average force on the ball by the racket is 98 N. The correct option is the third option - 98 N

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Answer:

We can determine the age of the Earth and the rocks found on Earth with techniques such as measuring ice cores and digging and analysing fossils.

Explanation:

Hopefully this helped!

Answer:

Tge Rhododendrob is the national flower of Nepal. The hills and mountain sides ranges of Nepal are decorated with diff colours and shapes

Answer:

a heat engine converts heat to mechanical energy.

electric generator

Vertical component = 40 m/s x sin(60) = 34.6 m/s

Answer: b. 34.6 m/s

Hi there!

a.

The equation for centripetal acceleration is as follows:

[tex]\large\boxed{a_c = \frac{v^2}{r}}}[/tex]

Plug in the given values to solve:

[tex]\large\boxed{a_c = \frac{(65)^2}{75} = 56.33 m/s^2}[/tex]

b.

According to Newton's Second Law:

[tex]\large\boxed{\Sigma F = ma}}[/tex]

The acceleration is v²/r, so the net force is:

[tex]\large\boxed{\Sigma F = m(\frac{v^2}{r})}}[/tex]

Multiply by the given mass:

[tex]\large\boxed{\Sigma F = 700(56.33) = 39433.33 N}}[/tex]

c.

There is NO net force in the vertical direction since the object is NOT accelerating in the vertical direction (normal force and weight cancel).

Thus, the ONLY net force experienced by the object is in the horizontal direction and is EQUAL to the centripetal force.

Your speed when your car hits a fixed object is 60 mph.

The given parameters:

Relative velocity tells us how fast we are traveling from a fixed point or reference point.

Thus, we can conclude that your speed when your car hits a fixed object is 60 mph.

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[tex]\\ \sf\Rrightarrow K.E=\dfrac{1}{2}mv^2[/tex]

[tex]\\ \sf\Rrightarrow K.E=\dfrac{1}{2}(40)(1)^2[/tex]

[tex]\\ \sf\Rrightarrow K.E=20J[/tex]

[tex]\\ \sf\Rrightarrow K.E=\dfrac{1}{2}(80)(1)^2[/tex]

[tex]\\ \sf\Rrightarrow K.E=40J[/tex]

The specific heat capacity of tungsten given the data from the question is 0.17 J/gºC

Mass of tungsten (M) = 100 g

Temperature of tungsten (T) = 100 °C

Mass of water (Mᵥᵥ) = 200 g

Temperature warm water (Tᵥᵥ) = 20 °C

Specific heat capacity of the water (Cᵥᵥ) = 4.184 J/gºC

Equilibrium temperature (Tₑ) = 21.6 °C

Specific heat capacity of tungsten (C) = ?

Heat loss = Heat gain

MC(T – Tₑ) = MᵥᵥCᵥᵥ(Tₑ – Tᵥᵥ)

100 × C × (100 – 21.6) = 200 × 4.184(21.6 – 20)

100 × C × 78.4 = 1338.88

Divide both sides by 100 × 78.4

C = 1338.88 / (100 × 78.4 )

C = 0.17 J/gºC

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By Newton's second law, the car slows down with an average acceleration a such that

-7100 N = (1500 kg) a   ⇒   a ≈ -4.7 m/s²

If we treat the car as accelerating uniformly with this magnitude, then the car slides a distance ∆x such that

0² - (25 m/s)² = 2a ∆x   ⇒   ∆x ≈ 66 m

The car slide before it comes to rest will be 66 m. Newton's second equation of motion is applied in this problem.

Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.

Force is defined as the product of mass and acceleration. Its unit is Newton.

The acceleration is found as;

F=ma

-7100 N = (1500 kg) a

a= -4.7 m/s²

If we assume that the automobile accelerates uniformly with this magnitude, the car slides x distance. From the Newton's second equation of motion;

v²=u²+2as

v²-u²=2as

0² - (25 m/s)² =2×(-4.7) s  

s=66 m

Hence,the car slide before it comes to rest will be 66 m.

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Explanation:

As you can see in the picture, we want the swimmer to go on a straight line, so the speed of the water must be equal to the speed of the swimmer along the x-axis. We also know the value of v, so we can calculate the of the cosine of the angle (alpha) between Vx and V. Thanks to the fundamental relation of gioniometry (cos^2(x) + sin^2(x) = 1) we can find the sine of alpha and calculate Vy. With Vy we can calculate the time that the swimmer will use for reaching the dock: s = Vy * t => t = s/(Vy).

I'll let you do all the calculations, you just have to plug in values.

a)The direction that she must aim herself through the water to arrive at the dock will be 73.7°.

b)The time it takes for the swimmer to cross the river will be 240 seconds.

Speed is defined as the rate of change of the distance or the height attained. it is a time-based quantity. it is denoted by u for the initial speed while v for the final speed. its si unit is m/sec.

Given data;

The maximum speed of the swimmer In still water,v=1.25m/s.

Speed of river = 0.35m/s [E]

α is the direction that she must aim herself through the water to arrive at the dock.

t is the time it takes for the swimmer to cross the river

The distance from the starting point to the dock is,s = 300 m

If the swimmer were to swim straight, the water's speed along the x-axis would have to match that of the swimmer.

[tex]\rm v_w = v_x = 0.35 \ m/sec[/tex]

α is the angle between vx and v

The value of the

[tex]\rm cos \alpha = \frac{v_x}{v} \\\\ \alpha = cos ^{-1}(\frac{0.35}{1.25} )\\\\ \alpha = 73.7 ^0[/tex]

The time that the swimmer will use for reaching the dock;

s = V×t

t = s/(v)

t=300 m / 1.25 m/sec

t = 240 seconds

Hence, the direction that she must aim herself through the water to arrive at the dock. and it takes for the swimmer to cross the river will be 73.7° and 240 seconds respectively.

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Answer:

because of the gravity of the earth

Answer:

when it is released the reading will be zero because gravitational force acts on it you can also say as free fall body

Explanation:

The output work is always less than the input work because some of the input work is used to overcome friction.

Answer:

Did you forget the answers

Explanation:

if so leave in comments and i will try to figure out

Answer:

what is the question and the answers??

Answer: When a child is riding on a sled down a steep, snow-covered hill, his elevation decreases and hence Kinetic energy increases and potential energy decreases.

i think this will help you

The Earth's orbital period change is A: It would increase by 0.15 years

Using Kepler's third law which states that the square of the orbital period of the planet is directly proportional to the cube of its distance from the sun.

So, T² ∝ R³

T'²/T² = R'³/R³ where

So, making T' subject of the formula, we have

T' = [√(R'/R)³]T

T' = [√(1.1 AU/1 AU)³] × 1 year

T' = [√(1.1)³] × 1 year

T' = √1.331 × 1 year

T' = 1.15 × 1 year

T' = 1.15 years.

So, the change in the Earth's orbital period ΔT = T' - T

= 1.15 years - 1 year

= 0.15 years

Since this is positive, the orbital period increases by 0.15 years.

So, the Earth's orbital period change is A: It would increase by 0.15 years

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Answer:

friction. or gravity both ofbthem .....................

..

Answer:

i can

Explanation:

i know what's the answer

Answer:

A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. The most likely phase of the substance is liquid.

A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. What is most likely the phase of the substance?

gas. NO. Gases have expansibility, that is, they occupy all the space available, so they wouldn't occupy just one half of the container.

liquid. YES. The description fits the liquid phase.

solid and gas. NO. Solids occupy fixed positions and their atoms can't slide past each other.

liquid and solid. NO. Solids can't be present due to their lack of movement.

A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. The most likely phase of the substance is liquid.

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Explanation:

Answer:

500 J.

Explanation:

Work done = force * distance

= 25 * 20

= 500 Joules.

Momentum is conserved, so

(2 kg) (50 m/s) + (4 kg) (-25 m/s) = (2 kg) v₁' + (4 kg) v₂'

where v₁' and v₂' are the velocities of the two blocks after the collision. Simplifying this gives

100 kg•m/s - 100 kg•m/s = (2 kg) v₁' + (4 kg) v₂'

0 = (2 kg) v₁' + (4 kg) v₂'

v₁' = -2v₂'

Energy is also conserved, so

1/2 (2 kg) (50 m/s)² + 1/2 (4 kg) (-25 m/s)² = 1/2 (2 kg) (v₁')² + 1/2 (4 kg) (v₂')²

Simplifying yields

2500 J + 1250 J = (1 kg) (v₁')² + (2 kg) (v₂')²

3750 J = (1 kg) (v₁')² + (2 kg) (v₂')²

Substitute v₁' = -2v₂' and solve for v₂' :

3750 J = (1 kg) (-2v₂')² + (2 kg) (v₂')²

3750 J = (6 kg) (v₂')²

(v₂')² = 625 J/kg = 625 m²/s²

v₂' = 25 m/s

Then the first block has final velocity

v₁' = -2 (25 m/s)

v₁' = -50 m/s