How many degrees are there between the direction of motion and the force of friction?
A. O
B. 270
C. 90
D. 180
The correct option is (d).
Angle should be 180° between the direction of force and the direction of motion of a body as work done is equal to force multiplied by displacement multiplied by cosx.
Friction is a force that opposes motion. When two objects are in contact, friction is acts in a direction opposite to the motion of the object.A force known as friction prevents relative motion between surfaces that are in touch. One of the more basic features of friction is that it always runs parallel to the surfaces with which it makes contact and opposes any motion or attempted motion of the systems with respect to one another.What is the direction of friction force?When a force is applied to stop it from moving, frictional force provides resistance. As a result, it always moves in the opposite direction of an item in motion. Friction acts on the right when force is applied to the left.Learn more about direction of friction force brainly.com/question/24322020
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A 0.225 kg sample of tin initially at 97.5°c is dropped into 0.115 kg of water. the initial temperature of the water is 10.0°c. if the specific heat capacity of tin is 230 j/kg • °c, what is the final equilibrium temperature of the tin-water mixture
Answer:
The final equilibrium temperature of the tin-water mixture is approximately 18.468 °C
Explanation:
The parameters of heat energy transfer from the tin to the water are given as follows;
The mass of the sample of tin, m₁ = 0.225 kg
The initial temperature of the tin, T₁ = 97.5 °C
The mass of the water into which the tin is dropped, m₂ = 0.115 kg
The initial temperature of the water, T₂ = 10.0 °C
The specific heat capacity of tin, c₁ = 230 J/(kg·°C)
The specific heat capacity of water, c₂ = 4,200 J/(kg·°C)
Let 'T' represent the final equilibrium temperature of the tin-water mixture, we have;
The heat lost by the tin, ΔQ[tex]_{tin}[/tex] = The heat gained by the water ΔQ[tex]_{water}[/tex]
∴ ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex]
Where;
ΔQ[tex]_{tin}[/tex] = m₁·c₁·(T₁ - T)
ΔQ[tex]_{water}[/tex] = m₂·c₂·(T - T₂)
By substitution, we have;
ΔQ[tex]_{tin}[/tex] = 0.225 kg × 230 J/(kg·°C) × (97.5°C - T)
ΔQ[tex]_{water}[/tex] = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
From ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex], we have;
0.225 kg × 230 J/(kg·°C) × (97.5°C - T) = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
∴ 5,045.625 J - 51.75 J/°C × T = 483 J/°C × T - 4,830 J
5,045.625 J + 4,830 J = 534.75 J/°C × T
∴ 534.75 J/°C × T = 9,875.625 J
T = 9,875.625 J/(534.75 J/°C) = 18.4677419 °C ≈ 18.468 °C
The final equilibrium temperature of the tin-water mixture, T ≈ 18.468 °C.
Rain and wind place which type of load on structures?
A) Dynamic load
B) Soft load
C) Gradual load
D) Static load
which of the following correctly describes the hierarchy of genetic material within a cell
Answer: D- Each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA
Explanation:
A macromolecule is a large molecule that is made of many smaller units. Chromosomes are macromolecules that contain all of the genetic information in a cell. Chromosomes are each made of two smaller units called chromatids. Chromatids are each made up of molecules of DNA. Therefore, the correct description of the hierarchy of genetic material in a cell is that each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA. The structures become more and more microscopic as one moves down the hierarchy.
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