help me with this. its scienceee

Answer:

rock of mass m is dropped to the ground from a height h. A second rock, with mass 2m, is dropped from the same height. When the second rock strikes the ground, what is its kinetic energy? (a) Twice that of the first rock, (b) four times that of the first rock, (c) same as that of the first rock, (d) half as much as that of the first rock, (e) impossible to determine.

If a  rock is dropped into a canyon that is 0.3 km deep, then the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.

There are three equations of motion given by  Newton

v = u + at

S = ut + 1/2 × a × t²

v² - u² = 2 × a × s

Keep in mind that these calculations only apply to uniform acceleration.

As given in the problem, if a rock is dropped into a canyon that is 0.3 km deep.

By using the second equation of motion given by Newton,

S = ut + 1/2at²

300 = 0 + 0.5 × 9.8 × t²

t² = 300 / 4.9

t = 7.82 seconds

Thus,  the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.

To learn more about equations of motion here, refer to the link given below  ;

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Answer:

B

hdhdududydysgd

hdhdgdtdtdt

gsgdgdggd

Explanation:

I TIHNK IS THE ANSWER

Answer:

C

Explanation:

Wave length is - - - - >

Bsjejwakknsbsbehebebbdbdbs

Answer:

Transverse wave

Explanation:

. . .

. . .

. . .

!

.

Your answer is 0.30 seconds

Answer:

i need points

Explanation:

i need points

Answer:

this is old so-

Explanation:

Answer:

five dollars

Explanation:

im thick lol

Answer:

The medium sound waves

Explanation:

change in the direction of a wave passing from one medium to another.

Answer:

50.93 m/s

199.5 kW

Explanation:

From the question, the nozzle exit diameter = 5 cm, Radius= diameter/2= 5cm/2= 2.5cm. we can convert it to metre for unit consistency= (2.5×0.01)=

0.025m

We can calculate the The cross sectional area of the nozzle as

A= πr^2

A= π ×0.025^2

= 1.9635 ×10^- ³ m²

From the question, the water is moving through the pipe at a rate of 0.1 m /s , then for the water to move through it at a seconds, it must move at

(0.1 / 1.9635 ×10^- ³ m²)

= 50.93 m/s

During the Operation of the pump, the Dynamic energy of the water= potential energy provided there is no loss during the Operation

mgh = 1/2mv²

We can make "h" subject of the formula, which is the height of required head of water

h = (1/2mv²)/mg

h= v² / 2g

h = 50.93² / (2 ×9.81)

h = 132.21m

From the question;

The total irreversible head loss of the system = 3 m,

the given position of nozzle = 3 m

the total head the pump needed=(The total irreversible head loss of the system + the position of the nozzle + required head of water )

=(3 + 3 + 132.21m)

=138.21m

mass of water pumped in a seconds can be calculated since we know that mass is a product of volume and density

Volume= 0.1m³

Density of sea water=1030 kg/m

(0.1 m^3× 1030)

= 103kg

We can calculate the Potential enegry, which is = mgh

= (103 ×9.81 × 138.21)

= 139651.5 Watts

= 139.65kW

To determine required shaft power input to the pump and the water discharge velocity

Energy= efficiency × power

But we are given efficiency of 70 percent, then

139651.5 Watts = 0.7P

=199502.18 Watts

P=199.5 kW

Therefore, the required shaft power input to the pump and the water discharge velocity is 199.5 kW

Answer:

i think it is newtons third law of motion but i'm not sure sorry.i just really need point i don't know the answer.

Explanation:

Answer:

force normal = mass times acceleration

F=ma

54= m (3.8)

divide by 3.8 in both sides

54/3.8

mass of the little brother is 14.2 kg

Answer:

1) False

2) True

3) 36N

Explanation:

1) Quantitative observation is related to number of objects . But in that example , there isn't any number.

2) Potential energy depends on height. So potential energy increases when height increases.

3) F = m×a

In the question , m = 18 kg ; a = 2m/s^2

So, F = 18×2 = 36N

Answer:

Explanation:

Incandescent bulbs are extremely inefficient because 90% of the energy is wasted as heat, with only 10% being converted to visible light. This gives incandescent bulbs a luminous efficiency rating of around 2%. Ultimately, incandescent bulbs perform better as heaters than as light sources.

Answer:

More common in adults.

Explanation:

Explanation:

Exothermic

Because here Energy is released.

Answer:

c

Explanation:

You must turn on your headlights whenever you use your windshield wipers. The correct option is option B.

In many jurisdictions, it is a legal requirement to turn on your headlights whenever you are using your windshield wipers. This is because using windshield wipers typically indicates reduced visibility due to rain, snow, or other adverse weather conditions.

By turning on your headlights, you increase your visibility to other drivers on the road, enhancing safety.

Therefore, You must turn on your headlights whenever you use your windshield wipers. The correct option is option B.

To know more about windshield wipers:

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Answer:

circular

Explanation:

Answer:

0.5

Explanation:

u must simplyfiy

Answer:

unbalanced and contact

Explanation:

The two terms that bests describes the net force acting on the sled is an unbalanced and contact force.

Force is a pull or push on a body. We have two main types of forces. Contact forces acts on a body and they must be in touch with it. An example is frictional force.

Non - contact forces acts based on force field and they are not in contact with the body. An example is gravitational force.

Therefore, the force on the wagon is an unbalanced and contact force.

Answer:

the more massive train i think

Explanation:

more mass means kinda more energy so it will take it longer to slow since it is   larger

Answer:

solar panels that charges battery

Answer:

non contant force

Explanation:

bcoz they push or pull on object without touching them

Answer:

energy

Explanation:

Answer:

...The earth has a great mass. Since mass and inertia are directly proportional to each other, the larger the mass of the object, the more inertia that it has. Inertia is the objects resistance to a change in motion.

Explanation:

Answer:

The speed with which the man flies after hitting the rock is 5.5 m/s

Explanation:

The given parameters are;

The mass of the man, m₁ = 100 kg

The mass of the scooter, m₂ = 10 kg

The initial speed of the man and the scooter, v₁ = 5 m/s

The speed with which the man flies after hitting the rock = v₂

The final speed of the scooter, v₃ = 0 m/s

The momentum = Mass × Velocity and by the principle of conservation of momentum, we have;

The total initial momentum = The total final momentum

The total initial momentum = (m₁ + m₂) × v₁ = (100 + 10) × 5 = 550

The total initial momentum = 550 kg·m/s

The total final momentum = m₁ × v₂ + m₂ × v₃, which gives;

The total final momentum = 100 × v₂ + 10 × 0

By conservation of momentum, the total initial momentum = The total final momentum, we get;

550 = 100 × v₂ + 10 × 0

∴ 550 = 100 × v₂

v₂ = 550 kg·m/s/(100 kg) = 5.5 m/s

The speed with which the man flies after hitting the rock = v₂ = 5.5 m/s

Answer:

The value is  [tex]x = 45.99 \ Au[/tex]

Explanation:

From the question we are told that

   The period of the  asteroid is   [tex]T = 176 \ years = 176 * 365 * 24 * 60* 60 = 5.55*10^{9}\ s[/tex]

Generally the average distance of the asteroid from the sun is mathematically represented as

            [tex]R = \sqrt[3]{ \frac{G M * T^2 }{4 \pi} }[/tex]

Here M is the mass of the sun with a value  

        [tex]M = 1.99*10^{30} \ kg[/tex]

         G  is the gravitational constant with value  [tex]G = 6.67 *10^{-11} \ m^3 \cdot kg^{-1} \cdot s^{-2}[/tex]

           [tex]R = \sqrt[3]{ \frac{6.67 *10^{-11} * 1.99*10^{30} * [5.55 *10^{9}]^2 }{4 * 3.142 } }[/tex]

=>       [tex]R = 6.88 *10^{12} \ m[/tex]

Generally

         [tex]1.496* 10^{11} \ m \to 1 Au (Astronomical \ unit )[/tex]

So

          [tex]R = 6.88 *10^{12} \ m \ \ \ \ \to \ \ x \ Au[/tex]

=>      [tex]x = \frac{6.88 *10^{12}}{1.496 *10^{11}}[/tex]

=>       [tex]x = 45.99 \ Au[/tex]

Answer:

a = - 5 [m/s²].

Explanation:

To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.

∑F = m*a

where:

F = resultant force [N] (units of Newtons)

m = mass = 50 [kg]

a = acceleration = 9.81 [m/s²]

For this particular problem, the only forces acting are the force of gravity acting down with negative sign, while the force of air opposes the fall, in this way it is positive.

[tex]f_{air}-F_{grav}=-m*a[/tex]

As the movement is pointing down the acceleration will be taken as negative.

[tex]740-(50*9.81)=-50*a\\740-490.5 = -50*a\\249.5 = -50*a\\a = - 5 [m/s^{2} ][/tex]

We should note that in this case, the acceleration has a negative sign, this means that the force of the air makes the skydiver move upwards

Answer:

A charged object in an electric field experiences a force due to the field. The electric field strength, E, at a point in the field is defined as the force per unit charge on a positive test charge placed at that point.

Explanation:

Answer:

When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance or (acceleration)

Explanation:

Answer:

I think it is but I don't know for sure

Explanation:

41 101001

41 is 101001 on the binary table i think