PLEASE HELP!!!!
A person pushes attempts to push a couch with a 25 N force. The couch, however, doesn't move. What is the static friction force acting on the couch? *
A. 25 N
B. 0 N
C. 50 N
D. There is no static friction the ONLY force acting on the couch is the push

Answer:

[tex]a=4\ m/s^2[/tex]

Explanation:

Given that,

Initial speed of a body, u = 0

Final speed of the body, v = 20 m/s

Time, t = 5 s

We need to find the acceleration of the body. We know that the acceleration of an object is equal to the rate of change of velocity divided by time taken. So,

[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{20-0}{5}\\\\a=4\ m/s^2[/tex]

So, the body's acceleration is equal to [tex]4\ m/s^2[/tex].

they have rubber and meatal so its going to get hot of course cause it a engine pushing and the gasoline is just all coming together but damage wise I still it the protection on that part to keep it from damage and life risk

I hope this may help

Answer:

Hello There!!

Explanation:

They are produced by the photodissociation of negatively charged hydrogen ions (H−).

hope this helps,have a great day!!

~Pinky~

Answer:

The coefficient of kinetic friction on the floor is 0.138

Explanation:

Given;

mass of the crate, m = 450 kg

force applied by the first worker, F₁ = 380 N

force applied by the second worker in the same direction as the first worker, F₁ = 230 N

frictional force opposing the motion of the box = -[tex]F_k[/tex]

Apply Newton's second law of motion;

∑F = ma

[tex]F_1 + F_2 - F_k = ma[/tex]

If the crate slides with constant speed, acceleration is zero (0).

[tex]F_1 + F_2 - F_k = ma = 0\\\\F_1 + F_2 - F_k = 0\\\\F_k = F_1 + F_2\\\\\mu _kmg= F_1 + F_2\\\\\mu _k = \frac{F_1 + F_2}{mg} \\\\\mu _k = \frac{380 + 230}{450 \times 9.8} \\\\\mu _k = 0.138[/tex]

Therefore, the coefficient of kinetic friction on the floor is 0.138

A red apple reflects Red light and absorbs all other colours.

speed = 40 m/s

Explanation:

Since the object is dropped, V0y = 0.

Vy = V0y - gt

= -(10 m/s^2)(4 s)

= -40 m/s

This means that its velocity is 40 m/s downwards. Its speed is simply 40 m/s.

The speed acquired by a freely falling object 4 seconds after being dropped from a rest position would be 40 meters/seconds.

There are three equations of motion given by  Newton

The first equation is given as follows

v = u + at

the second equation is given as follows

S = ut + 1/2×a×t²

the third equation is given as follows

v² - u² = 2×a×s

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

As given in the problem, we have to find the speed acquired by a freely falling object 4 seconds after being dropped from a rest position,

By using the first equation of motion,

v = u + at

initial velocity(u) = 0 m/s

acceleration(a) = 10 m/s²

v = 0 + 10×4

v = 40 meters/seconds

Thus, the speed acquired by a freely falling object 4 seconds after being dropped from a rest position would be 40 meters/seconds.

Learn more about equations of motion from here,

brainly.com/question/5955789

#SPJ2

Answer:

Mass = 30.46 kg

Explanation:

Given the following data;

Spring constant = 45 N/m

Acceleration = 1.3 m/s²

Extension = 0.88 m

To find the mass of the box;

First of all, we would determine the force acting on the spring.

Force = spring constant * extension

Force = 45 * 0.88

Force = 39.6 N

Next, we find the mass using Newton's second equation of motion.

Force = mass * acceleration

39.6 = mass * 1.3

Mass = 39.6/1.3

Mass = 30.46 kg

Answer:

b. False

Explanation:

The visible matter that belongs to the Milky way Galaxy are traced out to be about 50 kpc distance from the center.

Kpc stands for kiloparsec. It is the unit of measurement of distance.

A parsec is[tex]$\text{ used to measure large distances}$[/tex] of the astronomical objects that lies [tex]$\text{outside the solar system}$[/tex], mainly where galaxies are involved.

1 kiloparsec is 1000 parsec and is equal to 3260 light years.

So the visible matter is about 163,078 light years away.

Hence the answer is FALSE.

forces: forces applied to an object in opposite directions that are not equal in size. Unbalanced forces result in a change in motion. friction: the force that opposes the motion or tendency toward motion of two objects that are in contact.

Answer:

speed=distance covered/time taken

=75/2

=37.5 km/hr

Explanation:

average speed = distance move/ time taken

= 75km/2h

= 37.5km/h

Answer:

The height of building should be 98.13 m plus the height of Daniel. Since the 63° was measured from his eye level.

Explanation:

Answer:

Centripetal acceleration = 0.79 m/s²

Explanation:

Given the following data;

Radius, r = 2.6 km

Time = 360 seconds

Conversion:

2.6 km to meters = 2.6 * 1000 = 2600 meters

To find the magnitude of centripetal acceleration;

First of all, we would determine the circular speed of the car using the formula;

[tex] Circular \; speed (V) = \frac {2 \pi r}{t}[/tex]

Where;

Substituting into the formula, we have;

[tex] Circular \; speed (V) = \frac {2*3.142*2600}{360} [/tex]

[tex] Circular \; speed (V) = \frac {16338.4}{360} [/tex]

Circular speed, V = 45.38 m/s

Next, we find the centripetal acceleration;

Mathematically, centripetal acceleration is given by the formula;

[tex] Centripetal \; acceleration = \frac {V^{2}}{r}[/tex]

Where;

Substituting into the formula, we have;

[tex] Centripetal \; acceleration = \frac {45.38^{2}}{2.6}[/tex]

[tex] Centripetal \; acceleration = \frac {2059.34}{2600}[/tex]

Centripetal acceleration = 0.79 m/s²

Answer:

B) Inertia is the resistance of any physical object

Answer: [tex]4.65\ m/s[/tex]

Explanation:

Given

Distance putty has to travel is 3.5 m

The initial speed of putty is 9.50 m/s

Using equation of motion to determine the velocity of putty just before it hits ceiling

[tex]v^2-u^2=2as[/tex]

[tex]\Rightarrow v^2-(9.5)^2=2(-9.8)(3.5)\\\\\Rightarrow v^2=9.5^2-68.6\\\Rightarrow v=\sqrt{90.25-68.6}\\\Rightarrow v=4.65\ m/s[/tex]

So, the velocity of putty just before hitting is [tex]4.65\ m/s[/tex]

What is the primary evidence used to determine how the Moon formed?

[tex]\huge\color{purple}\boxed{\colorbox{black}{♡Answer}}[/tex]

A. Moon craters and Earth craters were caused by the same asteroid strike. ✅

[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]

Answer:

the number of electrons should equal to the the number of protons in a neutral atom

if there is a inequality between the numbers it means the atom has a + or - charge

Work is done when you lift an object to a certain height. If the force exerted is greater than the weight of the object, input work is greater than the output work. Then the extra energy goes in overcoming the gravitational acceleration and heating up of body etc

Answer:

4.408 [tex]\mathsf{M_{sun}}[/tex]

Explanation:

According to Kelper's Third Law, the equation of the combined mass (m₁+m₂) can be expressed as:

[tex](m_1 + m_2) = \dfrac{\text{(distance between stars)}^3}{\text{(orbital period)}^2}[/tex]

[tex]\text{combined mass}(m_1+m_2)} =\dfrac{(6.0)^3}{(7)^2} \ M_{sun}[/tex]

[tex]\text{combined mass}(m_1+m_2)} =\dfrac{216}{49} \ M_{sun}[/tex]

combined mass (m₁+m₂)  = 4.408 [tex]\mathsf{M_{sun}}[/tex]

Answer:

The speed of the bullet just before the impact is 701 m/s

Explanation:

Given;

mass of the bullet, m₁ = 20 g = 0.02 kg

mass of the block, m₂ = 2.8 kg

displacement of the block, d = 9 mm = 9 x 10⁻³ m

duration of motion of the bullet, t = 5 ms = 5 x 10⁻³ s

Apply the principle of conservation of energy;

The final kinetic energy of the bullet = maximum potential energy of the block

[tex]\frac{1}{2} m_1v^2 = m_2gh\\\\v^2 = \frac{2m_2gh}{m_1} \\\\v= \sqrt{\frac{2m_2gh}{m_1} } \\\\v = \sqrt{\frac{2 \times 2.8 \times 9.8 \times (9\times 10^{-3})}{0.02} } \\\\v = 4.97 \ m/s[/tex]

Apply the principle of conservation of linear momentum, to determine the initial velocity of the bullet before the impact.

m₁u₁  +  m₂u₂  =  v(m₁  +  m₂)

where;

u₁ is the initial velocity of the bullet

u₂ is the initial velocity of the block = 0

m₁u₁  +  0  = v(m₁  +  m₂)

m₁u₁  =  v(m₁  +  m₂)

0.02u₁ = 4.97(2.8 + 0.02)

0.02u₁ = 14.02

u₁ = 14.02 / 0.02

u₁ = 701 m/s

Therefore, the speed of the bullet just before the impact is 701 m/s

Answer:

The correct solution is "14.6875 kg".

Explanation:

Given values:

Force,

F = 47.0 N

Acceleration,

a = 3.20 m/s²

Now,

⇒ [tex]Force=Mass\times Acceleration[/tex]

or,

⇒       [tex]F=ma[/tex]

⇒    [tex]47.0=m\times 3.20[/tex]

⇒       [tex]m=\frac{47.0}{3.20}[/tex]

⇒           [tex]=14.6875 \ kg[/tex]

Answer:

100 cm

Explanation:

It is given that there are two loudspeakers that produces [tex]$\text{sound waves }$[/tex] along x-axis.

The maximum intensity of the sound is [tex]$\text{when the speakers are}$[/tex] at a distance of = 15 cm apart.

The sound intensity becomes zero when the separation between the speakers are increased and becomes 65 cm.

Therefore, the sound waves are in the phase, [tex]$\Delta x_1=15 \ cm$[/tex]

The sound waves are out of phase when [tex]$\Delta x_2=65 \ cm$[/tex]

Therefore,

[tex]$\Delta x_2 - \Delta x_1 = \frac{\lambda}{2}$[/tex]

[tex]$\lambda= 2(\Delta x_2 - \Delta x_1)$[/tex]

  = 2 (65 - 15)

  = 2 x 50

  = 100 cm

Hence the wavelength of the sound is 100 cm.

Answer:

[tex]R=2.78\ \Omega[/tex]

Explanation:

Given that,

The current flowing in the circuit, I = 3 A

The power of the battery, P = 25 W

We need to find the resistance of the battery. We know that the power of the battery is given by the formula as follows :

[tex]P=I^2R[/tex]

Put all the values to find R.

[tex]R=\dfrac{P}{I^2}\\\\R=\dfrac{25}{(3)^2}\\\\R=2.78\ \Omega[/tex]

So, the resistance is equal to [tex]2.78\ \Omega[/tex].

Answer:

the speed in -y

Explanation:

For this exercise we must use the right hand rule. The motion of a positive charge is given by.

Thumb points in the direction of speed

fingers extended in the direction of the magnetic field, + z axis

the palm in the direction of the force, as the charge is negative in the opposite direction of the force, axis + x

therefore the thumb is in the direction - y

the speed in -y

Answer:

A. It must stay the same, but kinetic energy (KE) can be transformed to PE and PE can be transformed to KE within the system.

Explanation:

Energy can be defined as the ability (capacity) to do work. The two (2) main types of energy are;

a. Potential energy (PE): it is an energy possessed by an object or body due to its position above the earth.

Mathematically, potential energy is given by the formula;

[tex] P.E = mgh[/tex]

Where,

b. Kinetic energy (KE): it is an energy possessed by an object or body due to its motion.

Mathematically, kinetic energy is given by the formula;

[tex] K.E = \frac{1}{2}MV^{2}[/tex]

Where;

Furthermore, the total energy of a physical object or body is the sum of the potential energy and kinetic energy possessed by the object or body.

Mathematically, it is given by the formula;

Total energy = P.E + K.E

The Law of Conservation of Energy states that energy cannot be destroyed but can only be transformed or converted from one form to another.

In this scenario, a system has both potential energy (PE) and kinetic energy (KE).

According to the law of conservation of energy, we can infer or deduce that the total energy of the system must stay the same because it cannot be destroyed, but kinetic energy (KE) can be transformed to potential energy (PE) and potential energy (PE) can be transformed to kinetic energy (KE) within the system.

Answer:

its number 2 one but i am not sure hope its right