Which statement describes friction?

Answer:

You and the car have inertia. If the car comes to a sudden stop, your body tends to keep moving forward. When the car starts moving again, your body tends to stay at rest. You move forward because the car seat exerts an unbalanced force on your body.

Explanation:

This is due to inertia. When the speeding bus stops suddenly, lower part of the body comes to rest while the upper part of the body tends to maintain uniform motion. Hence, the passenger's are thrown forward.

Answer:

C) 800

Explanation:

The conservation of mechanical energy allows finding the result for the speed of the pendulum when it is at 30º is:

The conservation of mechanical energy is a theorem of greater importance in physics and ordinary life, it states that if there is no friction force the total mechanistic energy remains constant at all points.

Mechanical energy is the sum of kinetic energy plus all potential energies. In the attachment we see a diagram of the pendulum's movement at the two points of interest.

They indicate that the pendulum is released from an initial angle of θ₁ = 60º, let's find the mechanical energy at that point.

      Em₀ = U = m g h

Where the height is measured from the lowest point of the movement.

      h = L - L cos tea1 = L (1 cos tea1)

The second point of interest occurs for θ₂ = 30º.

At this point part of the energy is indica and part gravitational potential.  

     [tex]Em_f[/tex]  = K + U₂

      [tex]Em_f[/tex] = ½ m v² + m g h ’

There is no friction in the system, therefore mechanical energy is conserved.

       Em₀ = Em₀_f

       mg L (1 - cos θ₁) = ½ m v² + m g L (1 - cos θ₂)

       v² = 2g L (cos θ₂ - cos θ₁)

Let's calculate.

       v² = 2 9.8 2.1 (cos 30 - cos 60)

       v² = 41.16 0.366

       v = 3.88 m / s

In conclusion using the conservation of mechanical energy we can find the result for the speed of the pendulum when it is at 30º is:

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Answer:

3.0 J

Explanation:

Just took the test

Answer: See explanation

Explanation:

Please see attached picture. Due to the fact one of the words in the equation F=ma contains a word not allowed.

Answer:

Part A: By using the formula, distance = speed x time

Part B: By using the formula, time = distance ( calculated in the first part) ÷ speed

Answer:

Can you rewrite that sorry

Explanation:

Answer:

Explanation:

The kinetic energy of an object can be found by using the formula

[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]

m is the mass

v is the velocity

From the question

m = 75 kg

v = 52 m/s

We have

[tex]k = \frac{1}{2} \times 75 \times {52}^{2} \\ = \frac{1}{2} \times 75 \times 2704 \\ = 75 \times 1352 \\ = 101400[/tex]

We have the final answer as

Hope this helps you

Answer:

true

Explanation:

Answer:

C, B, and D are ones i think i know that can occur during a physical change

Explanation:

A system in equilibrium has a moment sum of zero and the sum of upward

forces equal to the sum of the downward forces.

The correct values are;

The x and y component of the reaction at pin B are;

Bₓ = 1471.5 N

[tex]B_y[/tex] = 1103.625 N

The x and y component of the force at pin C are;

Cₓ = 588.6 N

[tex]C_y[/tex] = 220.725 N

Reasons:

The weight of the cylinder, W = 90 kg × 9.81 m/s² = 882.9 N

Considering member AB, gives;

[tex]\sum M_A[/tex] = [tex]B_y[/tex] × 2 - [tex]B_x[/tex] × 1.5 = 0 ⇒ [tex]B_y[/tex] = 0.75·Bₓ

Considering member CB, gives;

[tex]\mathbf{\sum M_C}[/tex] = -[tex]B_y[/tex] × 2 + 882.9 × 2.5 = 0 ⇒ [tex]B_y = \dfrac{882.9 \times 2.5}{2} = 1103.625[/tex]

[tex]B_y[/tex] = 0.75·Bₓ ⇒  [tex]B_x = \dfrac{B_y}{0.75} = \dfrac{1103.625}{0.75} = 1471.5[/tex]

The x and y component of the reaction at pin B are;

Bₓ  = 1471.5 N, [tex]B_y[/tex] = 1103.625 N

[tex]\mathbf{\sum F_y}[/tex] = 0 ⇒ -[tex]C_y[/tex] + [tex]B_y[/tex] - 882.9 = 0 ⇒ [tex]-C_y[/tex] + 1103.625 - 882.9 = 0

[tex]C_y[/tex] = 1103.625 - 882.9 = 220.725

[tex]\sum F_x[/tex] = 0 ⇒ -Cₓ + Bₓ - 882.9 = 0 ⇒ -Cₓ + 1471.5 - 882.9 = 0

Cₓ = 588.6

The x and y component of the reaction at pin C are;

Cₓ = 588.6 N, and [tex]C_y[/tex] = 220.725 N

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Answer:

[tex]\boxed {\boxed {\sf C. \ 20 \ m/s }}[/tex]

Explanation:

We are asked to find the initial speed of a car.

We are given the final speed, the time, and the acceleration, so we will use the following kinematic equation:

[tex]v_f=v_i+at[/tex]

We know the final speed is 40 meters per second, the acceleration is 4 meters per second squared, and the time is 5 seconds.

Substitute the values into the formula.

[tex]40 \ m/s = v_i+(4 \ m/s^2 * 5 \ s)[/tex]

Multiply inside the parentheses.

[tex]40 \ m/s =v_i+ 20 \ m/s[/tex]

We are solving for the initial speed, so we must isolate the variable [tex]v_i[/tex].  

20 meters per second is being added to [tex]v_i[/tex]. The inverse operation of addition is subtraction. Subtract 20 m/s from both sides of the equation.

[tex]40 \ m/s - 20 \ m/s = v_i + 20 \ m/s - 20 \ m/s[/tex]

[tex]40 \ m/s - 20 m/ s = v_i[/tex]

[tex]20 \ m/s=v_i[/tex]

The initial speed of the car is 20 meters per second and choice C is correct.

Answer:

C.

Explanation:

That is the main part of a cell, apart of the nervous system and controls all the other functions of the cell.

I hope this helped

Brainliest if it did? No pressure!

Have a great day! :D

A period of a satellite is the time taken by the satellite to travel round a

body.

The comparison between the periods  [tex]T_B[/tex], and [tex]T_A[/tex] is [tex]\underline {T_B = \dfrac{\sqrt{2} }{4 } \cdot T_A}[/tex]

Reason:

The period, T, of a satellite is given as follows;

[tex]T = 2 \cdot \pi \cdot \sqrt{\dfrac{r^3}{G \cdot M} }[/tex]

Volume of the planet A = [tex]\dfrac{4}{3} \cdot \pi \cdot r^3[/tex]

Mass of planet A, [tex]m_A[/tex] = [tex]\dfrac{4}{3} \cdot \pi \cdot r^3 \times \rho[/tex]

Volume of the planet B = [tex]\dfrac{4}{3} \cdot \pi \cdot (2 \cdot r)^3 = \dfrac{32}{3} \cdot \pi \cdot r^3[/tex]

Mass of planet B, [tex]m_B[/tex] = [tex]\dfrac{32}{3} \cdot \pi \cdot r^3 \times \rho[/tex]

Period of the satellite on planet A, [tex]T_A[/tex], is given as follows;

[tex]T_A = 2 \cdot \pi \cdot \sqrt{\dfrac{r^3}{G \times \dfrac{4}{3} \cdot \pi \cdot r^3 \times \rho} } = 2 \cdot \pi \cdot \sqrt{\dfrac{1}{G \times \dfrac{4}{3} \cdot \pi \times \rho} }[/tex]

Period of the satellite on planet B, [tex]T_B[/tex], is given as follows;

[tex]T_B = 2 \cdot \pi \cdot \sqrt{\dfrac{r^3}{G \times \dfrac{32}{3} \cdot \pi \cdot r^3 \times \rho} } = 2 \cdot \pi \cdot \sqrt{\dfrac{1}{G \times \dfrac{32}{3} \cdot \pi \times \rho} }[/tex]

Therefore, get;

[tex]\dfrac{T_A}{T_B} = \dfrac{ 2 \cdot \pi \cdot \sqrt{\dfrac{3}{G \times 4 \cdot \pi \times \rho} }}{ 2 \cdot \pi \cdot \sqrt{\dfrac{3}{G \times 32 \cdot \pi \times \rho} }} = \sqrt{\dfrac{32}{4} } = \sqrt{8} = 2 \cdot \sqrt{2}[/tex]

Therefore, [tex]T_A[/tex] = (2·√2)·[tex]T_B[/tex]

[tex]T_B = \dfrac{T_A}{2 \cdot \sqrt{2} } = \dfrac{\sqrt{2} \cdot T_A}{4 }[/tex]

The comparison between [tex]T_A[/tex] and  [tex]T_B[/tex] is therefore;

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A matter can be separated into three states.

Answer:

I would agree with your selection.

Explanation:

Answer:

You would need to save $300 every month to meet your savings goal.

Explanation:

4,500-900=3,600

3,600/12=300

Answer:

answer is 200

Explanation:

edge 2021

Answer:

The elastic limit of a material is the furthest

point it can be stretched or deformed while

being able to return to its previous shape.

Explanation:

Once a material has gone past its elastic

limit, its deformation is said to be inelastic.

The higher the spring constant, the stiffer

the spring.

The angular acceleration of the larger camshaft is 995.72 rad/s².

The given parameters;

The angular acceleration of the 3.75 cm camshaft is calculated as follows;

[tex]\omega _f = \omega _i + \alpha t\\\\\omega _f =0 + \alpha t\\\\\omega _f = \alpha t\\\\(1250 \ \frac{rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1\min}{60 \ s} ) = 0.032 \alpha \\\\130.92 = 0.032\alpha \\\\\alpha = \frac{130.92}{0.032} = 4091.25 \ rad/s^2[/tex]

The angular momentum of the camshaft is calculated as follows;

[tex]I_1 \alpha _1 = I_2 \alpha_2 \\\\\frac{1}{2} mr_1^2 \alpha _1 = \frac{1}{2}m R^2 \alpha_2\\\\r_1^2 \alpha _1 = R^2 \alpha_2\\\\\alpha_2 = \frac{r_1^2 \alpha _1 }{R^2} \\\\\alpha_2 =\frac{(0.037)^2 \times (4091.25)}{(0.075)^2} \\\\\alpha _2 = 995.72 \ rad/s^2[/tex]

Thus, the angular acceleration of the larger camshaft is 995.72 rad/s².

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Answer:

Explanation:

Total mechanical energy is

E = mgh + ½mv²

E = m(gh + ½v²)

E = 90(9.8(2.0) + ½4²)

E = 2,484 J answer b)

A person on a bike (m = 90 kg) is traveling 4 m/s at the top of a 2 m hill. the total energy of the biker would be 2484 Joules.

Mechanical energy is the combination of all the energy in motion represented by total kinetic energy and the total potential energy stored energy in the system which is represented by total potential energy.

As given in the problem a person on a bike (m = 90 kg) is traveling 4 m/s at the top of a 2 m hill.

The total kinetic energy of the biker

KE = 1/2 × m × v²

    = 0.5 × 90 × 4²

    = 720

Similarly, the total potential energy of the biker

PE = m × g × h

     =90 × 9.8 × 2

      = 1764 Joules

The total energy of the biker = 720 + 1764

                                                 = 2484 Joules

Thus, the total energy of the biker would be 2484 Joules .

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#SPJ2

Answer:

The question lacks a photo to fully answer correctly

If the fossil has its neck bent backwards towards its back, that is the common way to which dinosaurs died.

If the fossil is scattered a bit from its other linking fossil pieces, than it is most likely that the dinosaur was a meal to a predator.

Fossils that are in array but are divided clearly at a section suggests that land moved. Possibly earthquake or Pangea took place.

Answer:

Peripatus, which lived around 570 MYA, is in the top layer of rock. The trilobites that lived later, between 498 MYA and 445 MYA, appear in the bottom layer. Based on superposition, younger layers of rock are expected to be on top. The rock layers have been overturned, placing the younger layer on the bottom.

Explanation:

actually answer plauto

The velocity of the object is 4.1 m/s. Recall that the centripetal acceleration is the acceleration of a body moving in a circular path.

Given that the centripetal acceleration is obtained using the formula;

ac = v^2/r

ac= centripetal acceleration

v = velocity

r = radius

v^2 = rac

v= √ rac

ac = 5.6m/s^2

r = 3 meters

Substituting values;

v = √3 × 5.6m/s^2

v = √16.8

v = 4.1 m/s

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Answer:

Option A

Explanation:

N is Chloroplast, P is a large centralized vacuole and R is the cell wall which are found only in plant cells. Hence, the given cell is a plant cell.

S = Rough Endoplasmic Reticulum

P = Vacuole

O = Nucleus

T = Smooth Endoplasmic Reticulum

U = Golgi Apparatus

N = Chloroplast

U = Cell Membrane

M = Mitochondria

R = Cell wall

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Straight Path

Answer:

The spheres interact with one another, and a change in one might result in a change in another. Humans (biosphere) plough the fields with agricultural machinery made of geosphere materials, while the atmosphere (hydrosphere) provides precipitation to water the plants. The biosphere is home to all living organisms on the earth.

Explanation:

don't ask qestionsmm

Explanation:

s=(v^2-u^2)/2g

=(0-3^2)/2*10

= 0.45m