What is the angle of refraction?
15 degrees
30 degrees
74 degrees

Answer:

E) momentum and mechanical energy

Explanation:

In the context, an object is attached to the another mass with a spring which is initially at a rest position. Now when the spring is compressed, the two masses moves with the same speed. Now since the both the masses combines with the spring to move together they are considered as one system and in this case the momentum and the kinetic energy will be conserved.

The kinetic energy and momentum of the system after collision and the kinetic energy and momentum of the two masses before collision will be constant.

Answer:

it the last one

Explanation:

Answer:

1.2 x [tex]10^4[/tex] N

Explanation:

The centripetal force of a body moving in a circle is given by:

Centripetal force = [tex]\frac{Mv^2}{r}[/tex]

where M = mass of the object, v = velocity with which the object is moving, and r = radius of the circle.

In this case, M = 25,000 kg, v = 2.0 m/s, and r = 8.2 m. Hence;

Centripetal force generated by the whale = 25,000 x 2^2/8.2

                                            = 12,195.12 N = 1.2 x [tex]10^4[/tex] N to two significant digits.

Answer:

Explanation:

second one ??? pls i hope im right

Answer:

A bumper that crumbles (plato)

Explanation:

Answer:

250,000 Joules

Explanation:

The work required is the amount of energy added, so the answer is the difference in kinetic energy before and after the acceleration of the car.  (The problem doesn't say it's flat where the car is, but well assume it since there is no information about an elevation change that would require us to concern ourselves with potential energy!)

W = E_final - E_initial

= 1/2 m v_final^2 - 1/2 m v_initial^2

= 1/2 m (v_final^2 - v_initial^2)

= 1/2 (1000 kg) ( (30 m/s)^2 - (20 m/s^2) )

= 1/2 (1000 kg) (500 m^2/s^2)

= 250,000 kg m^2/s^2

= 250,000 Joules

Answer:

0.41s

8.01m/s

Explanation:

Using the formula; v = u + at

Where;

u = initial velocity (m/s)

v = final velocity (m/s)

t = time (s)

a = acceleration (m/s²)

According to the provided information, u = 4m/s, s = 8m,

V = u + at

4 = 0 + 9.8t

4 = 9.8t

t = 0.41s

b) v = u + at

v = 4 + 9.8(0.41)

v = 4 + 4.018

v = 8.018m/s

Answer: 0kg(m/s)

Explanation:

Answer:

D) it constantly reverses direction

Explanation:

Just took the test

Answer:

4th of August is the

Explanation:

5th and then I can help out by getting

Answer:

The final speed of the electron is 6,497 km/s

Explanation:

Given;

mass of the electron, m = 9.11 x 10⁻³¹ kg

electron potential, V = -120 V

Apply work energy theorem;

¹/₂mv² = eV

Where;

v is the final speed of the electron

e is the charge of the electron, = 1.602 x 10⁻¹⁹ C

[tex]v = \sqrt{\frac{2eV}{m} }\\\\v = \sqrt{\frac{2(1.602*10^{-19})(120)}{9.11*10^{-31}} }\\\\v = 6496473.75 \ m/s\\\\v = 6,497 \ km/s[/tex]

Therefore, the final speed of the electron is 6,497 km/s

Answer:

Abstinence is the best choice to prevent the consequences of sexual activity because you're putting yourself at lower risk to encounter STD's and STI's. Abstinence also prevents you from getting pregnant.

Explanation:

I got 100% on Edge.

Complete abstinence is the best choice to prevent the consequences of sexual activity because this prevents any type of sexual contact and STDs.

Abstinence is a self-enforced restraint from the indulging in bodily activities which are widely experienced as giving pleasure to people. Most frequently, abstinence refers to sexual abstinence, however it can also mean abstinence from alcohol, drugs, food, etc.

Complete abstinence is the only way which can guarantee protection against the infection with sexually transmitted diseases. This means avoiding all the types of intimate genital contact. Someone who is practicing complete abstinence does not have any type of intimate sexual contact. So, there is no risk of getting an STD.

Learn more about Sexual activity here:

https://brainly.com/question/6279240

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A rocket moves upward as the engine pushes downward against exhaust gases and the exhaust gases push upward against the engine.

Answer:

Work done, W = 18 kJ

Explanation:

Given that,

The mass of a refrigerator, m = 300 kg

The second floor of a house is 6 m above the street level.

We need to find the work required to lift the refrigerator to the second-story level.

Work done, W = F × d

Putting all the values,

W = 300 × 10 × 6

W = 18000 J

or

W = 18 kJ

So, 18 kJ of work is done in lifting the refrigerator to the second-story level.

Answer: 16

Explanation:

Sandra can take to lower her body fat percentage to eat several, balanced, low-calorie meals throughout the day and to exercise regularly.

When we can't access food for a lengthy period of time, fat is a vital source of stored energy.

There are several steps Sandra can take to lower her body fat percentage:

Exercise regularly: Regular physical activity, such as cardiovascular exercise, resistance training, and high-intensity interval training (HIIT), can help increase muscle mass and reduce body fat.

Eat a healthy diet: Eating a balanced diet that includes plenty of fruits, vegetables, whole grains, lean proteins, and healthy fats can help Sandra maintain a calorie deficit, which is necessary for reducing body fat. Avoiding processed foods, added sugars, and excessive amounts of saturated and trans fats can also be beneficial.

Control portions: Paying attention to portion sizes can help Sandra avoid overeating and maintain a calorie deficit. She can also use tools like measuring cups and a food scale to help control portion sizes.

Stay hydrated: Drinking enough water can help Sandra maintain a healthy metabolism and reduce feelings of hunger.

Get enough sleep: Getting adequate sleep (7-9 hours per night) can help regulate hormones that impact metabolism and hunger, making it easier to maintain a calorie deficit and reduce body fat.

Learn more about body fats here:

https://brainly.com/question/1495805

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Answer:

a

 [tex]W_s = 8[/tex]

b

[tex]P = 594 000 \ Pa[/tex]

Explanation:

Considering question a

 From the question we are told that

   The weight of the object in  air is  [tex]W_1 = 7.84 \ N[/tex]

    The weight of the object in water  is [tex]W_2 = 6.86\ N[/tex]

Generally the specific gravity of the object is mathematically represented as

       [tex]W_s = \frac{W_1 }{W_1 - W_2 }[/tex]

=>    [tex]W_s = \frac{7.84}{7.84 -6.86 }[/tex]

=>    [tex]W_s = 8[/tex]

Considering question b

From the question we are told that        

   The pressure required is  [tex]P_r = 300 \ kPa = 300 *10^{3} \ Pa[/tex]

    The height is  [tex]h = 30.0 \ m[/tex]

Generally the pressure require to get the water to  the given height is mathematically represented as

      [tex]P_h = \rho * g * h[/tex]

Here  [tex]\rho[/tex] is the density of  water with value  [tex]\rho = 1000 \ kg / m^3[/tex]

So  

     [tex]P_h = 1000 * 9.8 * 30[/tex]

=>  [tex]P_h = 294000 \ Pa[/tex]

Generally the pressure require to pump the water to  the given height at the require pressure is mathematically represented as

      [tex]P = P_h + P_r[/tex]

=>  [tex]P = 294000 + 300*10^{3}[/tex]

=>  [tex]P = 594 000 \ Pa[/tex]

Answer:

I think the answer should be an object's tendency to resist changes in motion.

Explanation:

Inertia is resistance of any physical object to any changes in its velocity.

Answer:

an object's tendency to resist changes in motion.

Explanation:

Answer:

Ancestors!

Explanation:

I know a thing or two~

Answer:

It depends on what the context is, if you mean people that came long before us you might be refering to ancestors, but if you mean people that came before us at any time then you would be refering to a predecessor.

Explanation:

Answer:

Explanation:

The density of a substance is defined as the mass per unit volume of the substance, the unit is in kg/m^3 and it is represented by the greek letter rho

Step one:

given data

we are told that the density  of Co2=  1.98 kg/m3

and the mass of Co2 is= 1.70 kg

we know the relation between mass, volume and density is

[tex]density=mass/volume[/tex]

make volume subject of formula we have

[tex]volume=mass/density[/tex]

substitute we have

[tex]volume=1.7/1.98\\\\volume= 0.85m^3[/tex]

Answer:

b

Explanation:

Answer:

In a collision, there is a collision force which endures for some amount of time to cause an impulse. This impulse acts upon the object to change its velocity and thus its momentum

Answer:

2 sig

Explanation:

1 and 7

Answer:

[tex]I=2\ kgm^2[/tex]

Explanation:

Given that,

Mass of a person, m = 72 kg

Force acting on a doorknob, F = 5 N

The doorknob is located 0.800 m from axis of the frictionless hinges of the door.

The angular acceleration of the dor, a = 2 rad/s²

We need to find the moment of inertia of the door about the hinges.

The person applies a torque to the door and it is given by :

[tex]\tau=Fr[/tex] ...(1)

Also, the torque is equal to :

[tex]\tau=I\alpha[/tex] ...(2)

From equation (1) and (2) we get :

[tex]Fr=I\alpha[/tex]

I is the moment of inertia

[tex]I=\dfrac{Fr}{\alpha }\\\\I=\dfrac{5\times 0.8}{2}\\\\=2\ kgm^2[/tex]

So, the moment of inertia of the door about the hinges is [tex]2\ kgm^2[/tex].

Answer:

Plate tectonic theory began in 1915, when Alfred Wegener developed his "continental drift" idea. Wegener believed that continents plowed through ocean basin crust, explaining why many coasts (such as those in South America and Africa) appear to fit together like a puzzle.

Answer:

B

Explanation:

Newton’s Second Law of Motion

Newton’s Second Law of Motion states that ‘when an object is acted on by an outside force, the mass of the object equals the strength of the force times the resulting acceleration’.

This can be demonstrated dropping a rock or and tissue at the same time from a ladder. They fall at an equal rate—their acceleration is constant due to the force of gravity acting on them.

The rock's impact will be a much greater force when it hits the ground, because of its greater mass. If you drop the two objects into a dish of water, you can see how different the force of impact for each object was, based on the splash made in the water by each one.

Answer:

b

Explanation:

Seems like some of your question is missin

Explanation:

Answer:

a

  [tex]x_2 = -2.3356[/tex]

b

 [tex]v = -1.384 \ m/s[/tex]

Explanation:

From the question we are told that

  The initial position of the particle is  [tex]x_1 = 0.180 \ m[/tex]

  The initial  velocity of the particle is  [tex]u = 0.060 \ m/s[/tex]

  The acceleration is   [tex]a = -0.380 \ m/s^2[/tex]

   The time duration is  [tex]t = 3.80 \ s[/tex]

Generally from kinematic equation

    [tex]v = u + at[/tex]

=>  [tex]v = 0.060 + (-0.380 * 3.80)[/tex]

=>  [tex]v = -1.384 \ m/s[/tex]

Generally from kinematic equation

   [tex]v^2 = u^2 + 2as[/tex]

Here s is the distance covered by the particle, so

   [tex](-1.384)^2 = (0.060)^2 + 2(-0.380)* s[/tex]

=>  [tex]s = -2.5156 \ m[/tex]

Generally the final position of the particle is  

    [tex]x_2 = x_1 + s[/tex]

=>   [tex]x_2 = 0.180 + (-2.5156)[/tex]

=>   [tex]x_2 = -2.3356[/tex]