David delivers meals to elderly people once a week. He uses a cart to move the meals. The cart has four smooth wheels. Which type of friction acts between the cartwheels and the sidewalk?

Answer:

I don't know sorry' please

Answer:

Efficiency of a machine is defined as the ratio of output work to input work in a machine . It is expressed in percentage and denoted by

η ( eta).

Answer:

5.0cm

Explanation:

To get the height of the image, we will use the magnification formula as shown:

m = Hi/H = v/u

Hi is the image height

H is the object height

v is the image distance

u is the object distance

First, we need to get the image distance v

Using the mirror formula;

1/f = 1/v+ 1/u

1/-6 = 1/v + 1/12

1/v = -1/12 - 1/6

1/v = -1-2/12

1/v = -3/12

v = 12/-3cm

v = -4cm

Next is to get the image height Hi

Using the expression;

Hi/H = v/u

Hi/15 = 4/12

Hi/15 = 1/3

3Hi = 15

Hi = 15/3

Hi = 5.0cm

Hence the image height is 5.0cm

Answer:

D. 5.0 cm

Explanation:

got it correct on the test

Answer:

why is fraction called a necessary evil

The heat for a temperature in plastic increases at the range of 50°C to 100°C then the plastic decreases its stiffness or flexural modulus.

It is given that the temperature is increased from 50°C to 100°C that means temperature is increasing.

It is required to state the effect of increase in heat on plastic.

The plastic starts to lose its stiffness or we say that it converts into a softened material as long as we increase the temperature of the material.

So if we increase the temperature too much or exceed above the limit of temperature range then it will distort.

Also there are many qualities that can be affected by increasing the temperature like mechanical property, material fatigue or chemical phenomenon.

Therefore, the heat for a temperature range of 50°C to 100°C

Plastic increases then the plastic decreases its stiffness or flexural modulus.

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Answer:

A. Cilvil court.........

Civil court  would you go to if you wanted to declare bankruptcy. The correct option is A.

Thus, According to the United States Bankruptcy Code, bankruptcy proceedings are typically filed in a federal bankruptcy court.

The federal court system includes these courts, which deal with Chapter 7, Chapter 11, and Chapter 13 bankruptcy cases.

The additional alternatives (U.S. Court of Appeals, Supreme Court, and U.S. District Court) are not the main courts where bankruptcy cases are generally filed.

Thus, Civil court  would you go to if you wanted to declare bankruptcy. The correct option is A.

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Answer:

980 newton

Explanation:

100×9.8 = 980

Answer:

Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.

Answer:

a plumber

Explanation:

Answer:

800N

Explanation:

as we know that

weight = mass × acceleration due to gravity

= 80kg × 10 m/s^2

= 800N.

Answer:

The scope of physics is quite vast and covers an enormous range of magnitude of physical quantities like mass, length, time, energy etc.

The scope is divided into two sections, where on one side it studies about phenomena at a very small microscopic level involving and analyzing electrons, protons, and neutrons.

Answer:

Part 1

20 N

Part 2

0.4 m/s²

Part 3

4 m/s

Explanation:

The force which pulls the sled right = 50 N

The friction force exterted towards left by the snow = -30 N

The mass of the sled = 50 kg

Part 1

The sum of the forces on the sled, F = 50 N + (-30) N = 20 N

Part 2

The acceleration of the sled is given as follows;

F = m·a

Where;

m = The mass of the sled

a = The accelertion

a = F/m

∴ a = (20 N)/(50 kg) = 0.4 m/s²

The acceleration of the sled, a = 0.4 m/s²

Part 3

The initial velocity of the sled, u = 2 m/s

The kinematic equation of motion to determine the speed of the sled is v = u + a·t

The speed, v, of the sled after t = 5 seconds is therefore;

v = 2 m/s + 0.4 m/s² × 5 s = 4 m/s.

Answer:

All objects on Earth, regardless of their mass, accelerate due to gravity at the same rate - that is, 9.8 m/sec2. The weight of an object can be calculated using the formula for force - F = m * a - where F equals the weight of the object and now the acceleration (a) is the acceleration of gravity (g).

Answer:

1) Can change the state of an object(rest to motion/ motion to rest):For example, pushing a heavy stone in order to move it. 2) May change the speed of an object if it is already moving. 4) May bring about a change in the shape of an object. For example, blowing air in balloon.

Explanation:

Effect of force Can change the state of an object(rest to motion/ motion to rest):For example, pushing a heavy stone in order to move it.

Converse:

if q , then p

Inverse:

If not p , the not q.

Contra Positive:

If not q, then not p.

If then statement is a conditional statement. In this statement there is some condition at the first part of the sentence and then in the second part there is a conclusion.

The example of if then sentence is as follows,

If this camel is thirsty, then it will drink water from the well.

In this example there is a condition in first part that if camel is thirsty, in the second part there is conclusion which states that then it will drink water from well.

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Answer:

The laws of liquid pressure are  

(i) Pressure inside the liquid increases with the depth from the free surface of the liquid.

(ii) Pressure is same at all points on a horizontal plane, in case of stationary liquid.

(iii) Pressure is same in all directions about a point inside the liquid.

(iv) Pressure at same depth is different in different liquids. It increases with the increase in the density of the liquid.

(v) A liquid will always seek its own level.

A Fluid is any liquid or gas or generally any material that cannot sustain a tangential, or shearing, force when at rest.  

Explanation:

Answer:

lemon

Explanation:

the lower the number the hier hydrogen ions

Answer: B

Explanation:

Answer:

a) v = 0.4799 m / s,  b)  K₀ = 1600.92 J,    K_f = 5.46 J

Explanation:

a) How the two players collide this is a momentum conservation exercise. Let's define a system formed by the two players, so that the forces during the collision are internal and also the system is isolated, so the moment is conserved.

Initial instant. Before the crash

        p₀ = m v₁ + M v₂

where m = 95 kg and his velocity is v₁ = -3.75 m / s, the other player's data is M = 111 kg with velocity v₂ = 4.10 m / s, we have selected the direction of this player as positive

Final moment. After the crash

       p_f = (m + M) v

as the system is isolated, the moment is preserved

       p₀ = p_f

       m v₁ + M v₂ = (m + M) v

       v =[tex]\frac{m v_1 + M v_2}{m+M}[/tex]

let's calculate

        v = [tex]\frac{ -95 \ 3.75 \ + 111 \ 4.10}{95+111}[/tex]

        v = 0.4799 m / s

b) let's find the initial kinetic energy of the system

         K₀ = ½ m v1 ^ 2 + ½ M v2 ^ 2

         K₀ = ½ 95 3.75 ^ 2 + ½ 111 4.10 ^ 2

         K₀ = 1600.92 J

the final kinetic energy

         K_f = ½ (m + M) v ^ 2

         k_f = ½ (95 + 111) 0.4799 ^ 2

         K_f = 5.46 J

Answer:

the ans is 120 degree hope it will help

Explanation:

hey

the answer is Brazil

hope it helps ✌

Answer:   Let us calculate the pressure exerted on the bottom by the weight of the fluid. That pressure is the weight of the fluid mg divided by the area A supporting it (the area of the bottom of the container): P=mgA P = m g A .

Explanation:

Answer:

The speed of the object when displacement is 0.041 meters is 0.375 meters per second.

Explanation:

First, we need to determine the angular frequency of the system ([tex]\omega[/tex]), in radians per second:

[tex]\omega = \sqrt{\frac{k}{m} }[/tex] (1)

Where:

[tex]k[/tex] - Spring constant, in newtons per meter.

[tex]m[/tex] - Mass, in kilograms.

If we know that [tex]k = 10\,\frac{N}{m}[/tex] and [tex]m = 0.36\,kg[/tex], then the angular frequency of the system is:

[tex]\omega = \sqrt{\frac{10\,\frac{N}{m} }{0.36\,kg} }[/tex]

[tex]\omega \approx 5.270\,\frac{rad}{s}[/tex]

The kinematic formulas for the position ([tex]x(t)[/tex]), in meters, velocity ([tex]\dot x(t)[/tex]), in meters per second, and acceleration of the object ([tex]\ddot x(t)[/tex]), in meters per square second, are:

[tex]x(t) = A\cdot \cos \omega t[/tex] (2)

[tex]\dot x(t) = -\omega \cdot A \cdot \sin \omega t[/tex] (3)

[tex]\ddot x(t) = -\omega^{2}\cdot A \cdot \cos \omega t[/tex] (4)

Where [tex]A[/tex] is the amplitude of the motion, in meters.

From (2) we determine the time associated with position [tex]x(t) = 0.041\,m[/tex] ([tex]\omega \approx 5.270\,\frac{rad}{s}[/tex], [tex]A = 0.082\,m[/tex]):

[tex]t = \frac{1}{\omega}\cdot \cos^{-1} \left(\frac{x(t)}{A} \right)[/tex] (5)

[tex]t = \frac{1}{5.270\,\frac{rad}{s} }\cdot \cos^{-1}\left(\frac{0.041\,m}{0.082\,m} \right)[/tex]

[tex]t = 0.199\,s[/tex]

And the speed of the object is:

[tex]\dot x(t) = -\left(5.270\,\frac{rad}{s} \right)\cdot (0.082\,m)\cdot \sin \left[\left(5.270\,\frac{rad}{s} \right)\cdot (0.199\,s)\right][/tex]

[tex]\dot x(t) \approx -0.375\,\frac{m}{s}[/tex]

The speed of the object when displacement is 0.041 meters is 0.375 meters per second.

Answer:

(i)  Electric field outside the shell:

For point r>R; draw a spherical gaussian surface of radius r.

Using gauss law, ∮E.ds=q0qend

Since E is perpendicular to gaussian surface, angle betwee E is 0.

Also E being constant, can be taken out of integral.

So, E(4πr2)=q0q

So, E=4πε01r2q

Answer:

D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires

Explanation:

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This speaks of equality in magnitude of force applied but in an opposite direction to one another.

According to this reaction, a car's tires exert a force on the track, this means that in accordance to Newton's third law, the track must exert an equal but opposite force on the car's tires. This causes the car to accelerate forward.

Answer:

"For towing, a tow chain should be of a length that keeps both vehicles within the maximum 4.5 meter distance, also  tow chains an be any length 20 foot chains are often chosen"  

Explanation:

-  https://letstowthat.com

Also Quick note the feet of tow rope or chain varies on the situation but most longest or 20 feet.  

Answer:

A submarine uses tanks that are filled with compressed air and when it is needed the air is released and takes on water which increase the density making it sink but when the water is pushed out the sub marine density is decreased making it float