The 5 kg red book is about to fall from a 2.1 m high bookshelf.

What is its PE?

Use g = 9.8 m/s2 for the acceleration due to gravity.

Answer:

6.53 m/s²

Explanation:

Let m₁ = 5 kg and m₂ = 10 kg. The figure is attached and free body diagrams of the objects are also attached.

Both objects (m₁ and m₂) have the same magnitude of acceleration(a). Let g be the acceleration due to gravity = 9.8 m/s². Hence:

T = m₁a               (1)

m₂g - T = m₂a    (2)

substituting T = m₁a in equation 2:

m₂g - m₁a = m₂a

m₂a + m₁a = m₂g

a(m₁ + m₂) = m₂g

a = m₂g / (m₁ + m₂)

a = (10 kg * 9.8 m/s²) / (10 kg + 5 kg) = 6.53 m/s²

Both objects have an acceleration of 6.53 m/s²

Answer:

Explanation:charged particles create an electric force field. Moving charged particles create a magnetic force field. Accelerating charged particles produce changing electric and magnetic force fields which propagate as EM waves.

Answer:

less energy is needed to heat the house

the roof is a better insulator

The correct advantage of having a roof with a lower thermal conductivity is Less energy is needed to heat the house. The correct answer is option 1.

A roof with lower thermal conductivity acts as a better insulator, reducing heat transfer between the interior and exterior of the house. This means that during colder months, less heat escapes through the roof, requiring less energy to maintain a comfortable temperature indoors. Additionally, a roof with lower thermal conductivity will help regulate indoor temperatures more effectively, making it a better insulator against external weather conditions. It does not directly affect the likelihood of roof leaks or increase the rate of energy transfer by conduction. Option 1 is correct.

To know more about thermal conductivity, here

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--The complete Question is, What are the advantages of having a roof with a lower thermal conductivity?

Which of the following two is correct

1. Less energy is needed to heat the house

2. The roof is a better insulator

3. The roof is less likely to leak

4. The rate of energy transfer by conduction is greater

5. Weather will have a greater effect on the temperature of the house. --

Answer: The velocity magnitude or the velocity direction chages.

Explanation:

According to Newton's second law of motion, the acceleration of a system moved in same direction and is also directly proportional to the external force which acts on it while inversely proportional to the mass. The formula is: a = F/m

Based on the question, since the object obtains acceleration, then it can be infered that there will be changes in the velocity magnitude or the direction as a result of the motion.

When two charged particles are moving toward each other, they bond and accelerate together.

To find the correct statement among all the options, we need to know about electromagnetic force.

Thus, we can conclude that the option (C) is correct.

Learn more about electromagnetic force here:

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Answer:

1) False

As the frequency can be defined as the number of times wave formed per unit time or in other words the numbers of a combination of a crest and trough forms. So the frequncy of a sound wave depends upon the source producing sounds

2)False

Diffraction is the process in which a light wave bends when they pass through a specified medium such as water.

3)True

hope it helps

Answer:

D. -23.8 m/s2​

Explanation:

Answer:

[tex]\text{B. }-14.0\:\mathrm{m/s^2}[/tex]

Explanation:

From Newton's 2nd Law, we have [tex]\Sigma F=ma[/tex].

Substituting given values, we get:

[tex]-35.0=2.50a,\\a=\frac{-35.0}{2.50},\\a=\boxed{-14.0\:\mathrm{m/s^2}}[/tex]

*Note the negative sign simply implies that the mass is travelling downwards (direction).

Answer:

Three requirements for selecting a unit are

1. The unit should be reproducible.

2. It should be possible to define the unit without ambiguity.

3. The value of the unit should not change with space and time.

Answer:

C

Explanation:

Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes, and 4 seconds with respect to other, distant, stars. Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation.

Answer: the answer is b.

ps: the other answer is wrong, the earth rotates around the sun, and the sun doesn't rotate around the earth.

Explanation:

Answer:

falseeee

Explanation:

You could hold rallies which attract a lot of people, they come and you discuss apon making the world a better place and how you want to shape the society.

Answer:

the answer is electromagnetic force because gravity is a force of attraction

Solution :

The relationship between the strength of magnetic field and the radiusof a charged particle's path is obtained through Newton's second law, which is given by :

F = ma

F = qvB and [tex]$a=\frac{v^2}{r}$[/tex]

Substituting these values in the second law of Newton,

[tex]$qvB=\frac{mv^2}{r}$[/tex]

Now solving for B, we get:

[tex]$B = \frac{mv}{rq}$[/tex]

  [tex]$=\frac{(1.67 \times 10^{-27})(5 \times 10^{7})}{2\times 1.6 \times 10^{-19}}$[/tex]

 = 0.261 T

The field strength can be obtained by using the technology of today.

Answer:

Negative

Explanation:

Answer:

H = 1.85 m

Explanation:

First, we will convert the height completely into inches. 1 feet contains 12 inches in it. Therefore:

H = (6 feet)(12 inch/1 feet) + 1 inch

H = 73 inches

Now, we will convert this height from inches to meters. 1 inch is equivalent to 0.0254 m. Therefore:

H = (73 inches)(0.0254 m/1 inch)

H = 1.85 m

Answer:

v = fy

speed is equal to frequency × wavelength

5 × 2

[tex]10m.s^{ - 1} [/tex]

Answer: 63 m/s

Explanation: If wheel drops vertically, you can use

conservation of energy : Ep = Ek.  mgh = ½mv^2  and

solve v = √(2gh ) = √ (2·9.81 m/s²·200 m) = 62.6 m/s.

NOTE: wheel has also horizontal speed which was not mentioned here.

Answer:

most common energy transformations is the transformation between potential energy and kinetic energy. In waterfalls such as Niagara Falls, potential energy is transformed to kinetic energy. The water at the top of the falls has gravitational potential energy. As the water plunges, its velocity increases.

Explanation:

Hope this helps you

( I got this from transformation and conservation article)

Answer:

An object at rest stays at rest as long as unbalanced forces act on it.

Explanation:

Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.

In physics, Sir Isaac Newton's First Law of Motion is known as Law of Inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.

The inertia of a physical object such as a truck is greatly dependent or influenced by its mass; the higher the quantity of matter in a truck, the greater will be its tendency to continuously remain at rest.

Hence, the situation which is contrary to Newton’s first law of motion is that, an object at rest stays at rest as long as unbalanced forces act on it.

According to Newton’s first law of motion, an object at rest stays at rest as long as unbalanced forces do not act on it.

Answer:

yes it right

Explanation:

cat

from the NASA website, COPYRIGHT Jun 8, 2015

Answer:

e. 4 rad/s

Explanation:

The maximum amount of angular velocity that can be reached by the disk can be found using the following formula:

[tex]v = r\omega\\\\\omega = \frac{v}{r}[/tex]

where,

ω = maximum angular velocity = ?

v = linear speed = 5 m/s

r = radius of disc = 1.5 m

Therefore,

[tex]\omega = \frac{5\ m/s}{1.5\ m} \\\\\omega = 3.33\ rad/s[/tex]

Therefore, the angular speed can be lower than this value due to frictional losses, but it can not exceed this value in the given linear speed limit of 5 m/s.

Hence, the correct option is:

e. 4 rad/s

Answer:

The correct answer will be:

(a) 27.3 m/s

(b) 3.8 s

Explanation:

According to the question:

Acceleration,

[tex]a= 4.2 \ m/s^2[/tex]

Time,

[tex]t = 6.5 \ s[/tex]

(a)

The gazelles top speed will be:

⇒  [tex]V_{max} = at[/tex]

             [tex]=4.2\times 6.5[/tex]

             [tex]=27.3 \ m/s[/tex]

or,

             [tex]= 27 \ m/s[/tex]

(b)

As we know,

s = 30 m

Now,

⇒  [tex]s = \frac{1}{2} at^2[/tex]

or,

⇒  [tex]t=\sqrt{\frac{2s}{a} }[/tex]

On putting the given values, we get

       [tex]=\sqrt{\frac{2\times 30}{4.2} }[/tex]

       [tex]=\sqrt{\frac{60}{4.2} }[/tex]

       [tex]=3.78 \ s[/tex]

or,

       [tex]=3.8 \ s[/tex]

Answer:

The answer is "[tex]55.05 \ \frac{J}{K}[/tex]"

Explanation:

Given value:

[tex]Q_m=4.184 \times 10^3 \ J\\T_0=100^{\circ}\\T_1=24^{\circ}[/tex]

Calculating the heat capacity of this chunk of metal:

Using formula:

[tex]C_m=\frac{Q_m}{T_0-T_1}\\[/tex]  

      [tex]=\frac{4.184 \times 10^3}{100 -24}\\\\=\frac{4.184 \times 10^3}{76}\\\\=55.05 \ \frac{J}{K}[/tex]

Answer:

See Explanation

Explanation:

a) We know that;

v = λf

Where;

λ = wavelength of the wave

f = frequency of the wave

v = velocity of the wave

So;

T = 2 * 2.10 s = 4.2 s

Hence f = 1/4.2 s

f = 0.24 Hz

The wavelength =  6.5 m

Hence;

v = 6.5 m * 0.24 Hz

v = 1.56 m/s

b)The amplitude of the wave is;

A =  0.600 m/2 = 0.300 m

c) Since the wave speed does not depend on the amplitude of the wave then the answer in (a) above remains the same

Where d = 0.30 m

A = 0.30 m/2 = 0.15 m