What is required for a sound wave to be reflected?

Answer:

It would be 20kg

Explanation:

This would be just 5x4 as there are 5 cats and each are 4kg. You can also add 4, 5 times as well.

I hope Im correct

Answer:

1360 m

Explanation:

Time taken for the thunder to travel the distance to the hikers = 4 seconds

Speed of the thunder = 340 m/s

Speed of light = 3×10⁸ m/s

It can be seen that the speed of light is substantially faster than the speed of sound. This is the reason why there is a delay in seeing the lightning and hearing the thunder.

Distance = Speed × Time

Hence, the lightning strike was 1360 m away from the hikers

Answer

3.340J

Explanation;

Using the relation. Energy stored in capacitor = U = 7.72 J

U =(1/2)CV^2

C =(eo)A/d

C*d=(eo)A=constant

C2d2=C1d1

C2=C1d1/d2

The separation between the plates is 3.30mm . The separation is decreased to 1.45 mm.

Initial separation between the plates =d1= 3.30mm .

Final separation = d2 = 1.45 mm

(A) if the capacitor was disconnected from the potential source before the separation of the plates was changed, charge 'q' remains same

Energy=U =(1/2)q^2/C

U2C2 = U1C1

U2 =U1C1 /C2

U2 =U1d2/d1

Final energy = Uf = initial energy *d2/d1

Final energy = Uf =7.72*1.45/3.30

(A) Final energy = Uf = 3.340J

Answer: the earth

Explanation: Earth exerts a gravitational pull on the moon 80 times stronger than the moon's pull on the Earth. Over a very long time, the moon's rotations created fiction with the Earth's tugging back, until the moon's orbit and rotational locked with Earth.

and that's why the earth pulls the moon

Final answer:

The Earth pulling on the moon and the moon pulling on the Earth exert the same amount of force on each other due to Newton's third law of motion.

Explanation:

In terms of force, the Earth pulling on the Moon and the Moon pulling on the Earth exert the same amount of force on each other. This is because of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. So, while the Earth's gravitational force pulls the Moon towards it, the Moon's gravitational force also pulls the Earth towards it with an equal amount of force.

Newton's third law of motion states that for every action, there is an equal and opposite reaction. In the context of the gravitational interaction between the Earth and the Moon, the forces they exert on each other are equal in magnitude and opposite in direction.

The Earth pulls on the Moon with a gravitational force, and, according to Newton's third law, the Moon simultaneously pulls on the Earth with an equal gravitational force. These forces are sometimes referred to as "action and reaction pairs." The force that the Earth exerts on the Moon is often called the gravitational attraction of the Earth on the Moon, and vice versa.

Learn more about gravitational force here:

brainly.com/question/32609171

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Answer:

The tension in the steel beam is 14.72 Newtons.

Explanation:

To calculate the tension in the steel beam when a car is hanging from it, you can use the principles of static equilibrium. In this situation, the gravitational force acting on the car must be balanced by the tension in the steel beam.

First, let's calculate the gravitational force acting on the car:

F_gravity = mass × gravity

Where:

Mass (m) = 1560 kg

Gravity (g) ≈ 9.81 m/s² (standard acceleration due to gravity)

F_gravity = 1560 kg × 9.81 m/s² ≈ 15306 N

Now, this gravitational force is balanced by the tension in the steel beam. Since the beam bends with an angle of 0.055°, we need to consider the vertical component of the tension force.

The vertical component of the tension (T_vertical) can be calculated using trigonometry (considering the angle θ):

T_vertical = T × sin(θ)

Where:

T_vertical is the vertical component of tension.

T is the tension in the beam.

θ is the angle in radians.

We need to convert the angle from degrees to radians:

θ = 0.055° × (π/180) ≈ 0.000959 radians

Now, we can calculate T_vertical:

T_vertical = 15306 N × sin(0.000959) ≈ 14.72 N

So, the tension in the steel beam is 14.72 Newtons.

Answer:

D=1.54489 m

Explanation:

Given data

S=6.10 mm= 0.0061 m

To find

Depth of lake

Solution

To find the depth of lake first we need to find the initial time ball takes to hit the water.To get the value of time use below equation

So ball takes 0.035sec to hit the water

As we have found time Now we need to find the final velocity of ball when it enters the lake.So final velocity is given as

Since there are (4.50-0.035) seconds left for (ball) it to reach the bottom of the lake

So the depth of lake given as:

Answer: d = 1.54m

The depth of the lake is 1.54m

Explanation:

The final velocity of the ball just before it hit the water can be derived using the equation below;

v^2 = u^2 + 2as ......1

Where ;

v is the final velocity

u is the initial velocity

a is the acceleration

s is the distance travelled.

Since the initial velocity is zero, and the acceleration is due to gravity, the equation becomes:

v^2 = 2gs

v = √2gs ......2

g = 9.8m/s^2

s = 6.10mm = 0.0061m

substituting into equation 2

v = √(2 × 9.8× 0.0061)

v = 0.346m/s

The time taken for the ball to hit water from the time of release can be given as:

d = ut + 0.5gt^2

Since u = 0

d = 0.5gt^2

Making t the subject of formula.

t = √(2d/g)

t = √( 2×0.0061/9.8)

t = 0.035s

The time taken for the ball to reach the bottom of the lake from the when it hits water is:

t2 = 4.5s - 0.035s = 4.465s

And since the ball falls for 4.465s to the bottom of the lake at the same velocity as v = 0.346m/s. The depth of the lake can be calculated as;

depth d = velocity × time = 0.346m/s × 4.465s

d = 1.54m

The depth of the lake is 1.54m