A rock dropped off a bridge takes 5 seconds to hit the water. Which of the following best represents the rock's speed just before impact?

Answer:

i) The reaction of the floor on the 50 kg man in the lift to lift up the man is 590 Newtons

ii) The reaction of the floor on the 50 kg man in the lift to move down the man is 390 Newtons

Explanation:

i) The acceleration of the lift upwards, a = 2 ms⁻²

The mass of the man standing in the lift, m = 50 kg

According to Newton's third law of motion, action and reaction are equal and opposite

Therefore, the force with which the elevator lifts the man = The reaction of the floor on the 50 kg man in the lift to lift up the man = The action of the man on the floor

∴ The force with which the elevator lifts the man up, F = The weight of the man, m·g + The force of the upward motion of the man, m·a

F = m·g + m·a

Where;

g = The acceleration due to gravity = 9.8 m/s²

m = The mass of the man = 50 kg

a = The acceleration of the lift = 2 m/s²

∴ F = 50 kg × 9.8 m/s² + 50 kg × 2 m/s² = 590 Newtons

The reaction of the floor on the 50 kg man in the lift to lift up the man = The force with which the elevator lifts the man up, F = 590 Newtons

ii) The reaction of the floor on the man when the acceleration of the lift is downwards, a = 2 ms⁻², is given as follows;

The force with which the elevator takes the man downwards, F = The reaction of the floor on the 50 kg man in the lift to lift up the man

The force with which the elevator takes the man downwards, F = The weight of the man, m·g - The force of the downward motion of the man, m·a

F = m·g - m·a

∴ F =  50 kg × 9.8 m/s² - 50 kg × 2 m/s² = 390 Newtons

The reaction of the floor on the 50 kg man in the lift to move down the man = The force with which the elevator takes the man downwards, F = 390 Newtons

Answer:

The answer is high

Explanation:

I just took the test :))

Higher frequency and higher pitch are produced by sounds with shorter wavelengths. So, long waves sound low and short waves sound high.

Physical characteristics of waves, such as transmission, reflection, polarization, diffraction, and refraction, are examples of wave attributes.

Waves are described mathematically using terms like wavelength, frequency, and amplitude.

Sound and light are two examples of common waves we encounter. Whether you're discussing waves or vibrations.

All of them may be classified according to the following four factors: amplitude, wavelength, frequency, and speed.

According to the graph, pitch perception is influenced by tone strength; below 1000 Hz, pitch tends to decrease with increasing loudness, and beyond 1000 Hz, pitch tends to increase.

Therefore, high pitch that is heard when waves are closely spaced together.

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My understanding of the concept of when a baby is considered alive is based on the medical, legal, and ethical standards provided by the scientific and medical communities, and it is not based on personal beliefs or opinions.

The determination of when a baby is considered alive is a complex and nuanced issue that is influenced by a variety of factors, including medical, legal, religious, and ethical considerations.

Therefore, it is important to consult with qualified professionals in each area to gain a better understanding of this topic.

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Complete Question:

What I your view on when the baby I alive? What standard or standard are you using to form your opinion?

Answer: \(12.82\ m/s\)

Explanation:

Given

Mass of car \(m=991\ kg\)

Force applied \(F=31,770\ N\)

time period \(t=0.4\ s\)

Acceleration associated with car

\(\Rightarrow a=\dfrac{F}{m}\\\\\Rightarrow a=\dfrac{31770}{991}\\\\\Rightarrow a=32.05\ m/s^2\)

Acceleration is the change in velocity w.r.t time

\(\Rightarrow a=\dfrac{\Delta v}{\Delta t}\\\\\Rightarrow 32.05=\dfrac{\Delta v}{0.4}\\\\\Rightarrow \Delta v=12.82\ m/s\)

thus, the change in velocity is \(12.82\ m/s\)

The period of the pendulum on the surface of Mars, where g = 3.71m/s², would be the same as the period on Earth, 1.70s.  The pendulum on the surface of Mars has a period of roughly 3.31 seconds, according to our calculation of this expression.

A basic pendulum's period is determined by the equation T = 2(L/g), where T is the period, L is the pendulum's length, and g is the acceleration brought on by gravity.

L = (T/(2))2g can be solved for on Earth with a period of 1.70s by rearranging the equation.

Using the same equation and the Mars surface gravity, g = 3.71m/s2, we can now get the period on Mars' surface: T\(_{mars}\) = 2(L/g\(_{mars}\)).

The equation T\(_{mars}\) = 2(((T/(2))2g)/(g\(_{mars}\))) is obtained by substituting the expression for L and the surface gravity of Mars.

T\(_{mars}\) = T(g/g_Mars), to simplify the formula.

T\(_{mars}\) = 1.70s(9.81m/s2 / 3.71m/s) is the result of plugging in the data. The pendulum on the surface of Mars has a period of roughly 3.31 seconds, according to our calculation of this expression.

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Answer:

75.8

Explanation:

because just divide 1.27 into 0.75 and there's your answer

Answer:

C. Test to see if your material is strong and works well.

The car's acceleration is -1.3 meters per the second square

To solve this, use the first equation of motion v=u+at

where, v = final velocity(meters per second )

           u = initial velocity(meters per second )

           a = acceleration(meters per second square)

           t = time (seconds)

According to the question,

Initial velocity(u) of the car = 28 meters per second

Final velocity(v) of the car  = 15 meters per second

Time  (t) = 10 seconds

Acceleration of the car(a) =?

Substituting the values in equation v =u+at

v= u+at

15 = 28 + ax10

15-28 = 10a

-13 = 10a

a = -13/10

a = -1.3 meters per second square

The car's acceleration is =  -1.3 meters per second square

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The acceleration of this car is equal to -1.3 meters per seconds square (m/s²).

Mathematically, the acceleration of this car can be calculated by using this mathematical expression:

a = (V - U)/t

Where:  

Substituting the given parameters into the acceleration formula, we have;

Acceleration, a = (15 - 28)/10

Acceleration, a = -13/10

Acceleration, a = -1.3 m/s².

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When the distance between the two charged particles is increased by a factor of 3, the force between them is decreased by a factor of 9.

Option B.

The electric force between two charged particles is determined by applying Coulomb's law.

Coulomb's law states that the force of attraction or repulsion between two charged particles is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges.

F = kq²/r²

where;

From the formula above, we can see that when the distance between two charged particles increases by a factor of 3, the force between them decreases by a factor of 9.

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The least horizontal force required to move the block is 4.0 N.

A force that holds an object at rest is called static friction.

The definition of static friction is: The resistance people feel when they attempt to move a stationary object across a surface without actually causing any relative motion between their body and the surface they are moving the object across.

Weight of the block = 16 N

The coefficient of friction between both surface is 0.25,

Hence, the least horizontal force required to move the block is = frictional resistance force

= 0.25 × 16 N

= 4 N.

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Answer:

D is the correct answer

Answer:

36.36 m/s

Explanation:

From the question,

Applying the law of conservation of momentum.

Total momentum before collision = Total momentum after collision .

mu+m'u' = V(m+m')................ Equation 1

Where m = mass of the rocket, m' = mass of the wood, u = initial velocity of the rock, u' = initial velocity of the wood, V = Final velocity after collision

But, the wood was initially at rest

Therefore, u' = 0 m/s

mu = V(m+m')

make V the subject of the equation

V = mu/(m+m')................. Equation 2

Given: m = 0.5 kg, u = 400 m/s, m' = 50 kg

Substitute these values into equation 2

V = (0.5×400)/(0.5+50)

V = 200/5.5

V = 36.36 m/s

Answer:

wavelength = (3×10^8 m/s)(6×10^5 Hz)

= 1.8×10^14 m

The acceleration of the airboat  is 2.2m/s^2 and starting from rest, it take the airboat to reach a speed of 12.0 m/s is 5.45s

Given mass of airboat (m) = 3.50 x 10^2kg

horizontal force of engine (F) = 7.70 x 10^2N

We know that from newtons laws of motion Force = mass x acceleration such that F = ma

(a) Now a = F/m = 7.70 x 10^2 / 3.50 x 10^2 = 2.2m/s^2

(b) Initial speed of airboat (u) = 0m/s

final speed (v) = 12m/s

We have acceleration a = 2.2m/s

Then we have another newtons law as: v = u+ at where t is the time taken

So t = v/a = 12/2.2 = 5.45s

Hence it takes to reach 5.45s a speed of 12m/s

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Answer:

(-10 + 20 -30) km right = -20 km right or -20 i km

where right is positive (X)  in a normal X-Y plane

The resultant displacement is 20 km left direction.

In mechanics, displacement refers to the distance that a particle or body moves in a particular direction. Generally, point masses are used to describe particles and bodies.

This means that, without sacrificing generality, bodies can be thought of as having all of their mass concentrated in a single mathematical point.

Displacement is a vector quantity as it has bot magnitude and direction. SI unit of displacement is meter.

The first displacement is = 10 km in left direction.

The second displacement is = 20 km in right direction.

The third displacement is = 30 km in left direction.

the resultant displacement is = ( 10 - 20 + 30) km left = 20 km in left direction.

Hence, the resultant displacement is  20 km in left direction.

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Sara walked north at 100 m/s. Han had a different velocity but the same speed. He could have walked. The answer is option D: Han could have walked north at 100 m/s.

Velocity is a vector quantity that includes both speed and direction. In this scenario, Sara walked north at a speed of 100 m/s. Now, for Han to have the same speed but a different velocity, he would also need to be moving at 100 m/s. However, the direction of his movement can vary. Option A states that Han could have walked south at 50 m/s. This would result in a different speed than Sara, so it doesn’t meet the given conditions. Option B suggests that Han could have walked north at 200 m/s. This violates the condition of having the same speed as Sara, as Han’s speed would be twice as fast.

Option C suggests that Han could have walked west at 100 m/s. Again, this violates the condition of having the same speed as Sara, as Han’s direction is different. Option D states that Han could have walked north at 100 m/s. This satisfies the condition of having the same speed as Sara and allows for a different direction of movement, making it the correct option. In summary, only option D, where Han walks north at 100 m/s, meets the requirement of having the same speed as Sara while allowing for a different direction of motion.

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When you remove the lid from a food container that has been left in a freezer for several months, the cold air inside the container causes the moisture inside the container to freeze onto the underside of the lid.

Food container that has been left in a freezer for several months we  discover a large collection of ice crystals on the underside of the lid this is due to the formation of a layer of ice crystals as the water vapor in the container condenses and freezes onto the cold surface of the lid. This process is known as sublimation and is why you find a layer of ice crystals on the underside of the lid.

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The force exerted by one plate for two parallel plates arrangement is F = QE/2.

The force exerted by one plate for two parallel plates arrangement is given as follows;

F = QE/2

where;

Thus, the force exerted by one plate for two parallel plates arrangement is F = QE/2.

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Answer:

The answers as per the given problem is solved in the segment below.

Explanation:

According to the question,

(a)

\(F=ILB\)

By putting the values, we get

   \(=10(2\times 10^4)(5\times 10^{-5})\)

   \(=10 \ N\)

(b)

\(W=Fx\)

or,

    \(=Fvt\)

    \(=10(7.80\times 10^3)(3600)\)

    \(=2.81\times 10^8 \ J\)

(c)

\(\frac{1}{2}mv'^2 =\frac{1}{2}mv^2-\omega\)

or,

      \(v=[v^2-\frac{2 \omega}{m} ]^\frac{1}{2}\)

         \(=[(7.8\times 10^3)^2-\frac{2(2.81\times 10^8)}{1\times 10^5} ]^{\frac{1}{2} }\)

         \(=7.79\times 10^3 \ m/s\)

now,

\(\Delta v=v-v'\)

     \(=0.36 \ m/s\)

(d)

The electric potential difference V(A) − V(B) is 80 V.

The electric potential difference V(A) − V(B) is 80 V.

The electric potential difference is calculated as follows:

V(A) - V(B) = - int_B^A E \cdot dr

where E is the electric field, dr is the displacement of the element in the electric field, and B and A are the two points between which we have to calculate the electric potential difference.

From the equation of electric field given,

E = 16i N/CDr for point A: dr_A = (8-3)\hat i +(-3-6)

hat j= 5\hat i-9\hat j

Dr for point B: dr_B = (3-8)\hat i +(6+3)\hat j

                                 = -5\hat i+9\hat j

Now, we need to calculate the electric potential difference.

So, putting all the given values in the above formula, we have:

V(A) - V(B) = - \int_B^A E \cdot dr

V(A) - V(B) = - \int_B^A 16i N/C .

(5\hat i-9\hat j) m

V(A) - V(B) = - \int_B^A -80 Nm/C

V(A) - V(B) = 80 V

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Answer:

read this it might help some

When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater collision force. When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater momentum change.

Explanation:

Answer:

Subscribe my Gaming channel Sameer Duos

Explanation:

Generally, a seismograph consists of a mass attached to a fixed base. During an earthquake, the base moves and the mass does not. The motion of the base with respect to the mass is commonly transformed into an electrical voltage. The electrical voltage is recorded on paper, magnetic tape, or another recording medium.

Answer:

-1m/s

Explanation:

We can calculate the speed of block A after collision

According to collision theory:

MaVa+MbVb = MaVa+MbVb (after collision)

Substitute the given values

5(3)+10(0) = 5Va+10(2)

15+0 = 5Va + 20

5Va = 15-20

5Va = -5

Va = -5/5

Va = -1m/s

Hence the velocity of ball A after collision is -1m/s

Note that the velocity of block B is zero before collision since it is stationary

Answer:

The correct answer is B

Lichens produce chemicals which dissolve and weather the rocks.

Minerals and vitamins are called micronutrients, therefore the correct answer is option 2, and simple carbohydrates come from foods such as vegetables and whole grains is true statement.

Science is the methodical, empirically-based pursuit and application of knowledge and understanding of the natural and social worlds.

A method of learning about the world is science. Science allows people to participate in the creation of new knowledge as well as use that knowledge to further their goals.

The correct response is option 2, and the statement that simple carbs originate from meals like vegetables and whole grains is true. Micronutrients include minerals and vitamins.

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Answer:

B

Explanation:

selenium is the right answer.

Jackson sells lemonade for $2 per cup. he paid $20 for supplies to sell 5 cups. What is the domain for this scenario

It is to be noted that Wellington, New Zealand, is most likely to experience: "Four Distinct Seasons" (Option D)

The seasons in Wellington are:

A season is a division of the year that is based on variations in weather, ecology, and the number of daylight hours in a particular place. Seasons on Earth are caused by the axial parallelism of Earth's tilted orbit around the Sun.

Seasons have a huge impact on vegetation and plant development. Winter weather is often chilly, with little sunshine and restricted plant development. Plants grow, tree leaves unfold, and flowers bloom in the spring. Summer is the hottest season with the greatest daylight, therefore plants grow fast.

Winter in Wellington is very brief and mild, with only a few frosty days. Wellington's temperature seldom rises over 25°C (77°F) or falls below 6°C (43°F).

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Full Question:

The map below [see attached] shows the locations of two cities in the southern hemisphere: a world map showing the location of wellington, new Zealand, a city located in the southern hemisphere at about 41 degrees latitude.

Wellington, New Zealand, is most likely to experience:

one distinct season

two distinct seasons

three distinct seasons

four distinct seasons

Answer:

I think A. would be brighter

Explanation:

Circuit A has only one bulb so it gets 100% of the electricity

Circuit B has two bulbs which means that they only get 50% of the electricity because it has to be split equally.

Hope it helps!