የምዕራፍ ማስታወሻዎችና የመልመጃ ጥያቄዎች

የ10ኛ ክፍል ፊዚክስ ምዕራፍ 3፦ ኢላስቲክነት እና ሪጅድ ቦዲ በስታቲክስ

በዚህ ገጽ ያለው ሁሉ ለ10ኛ ክፍል የፊዚክስ መፅሐፍ ምዕራፍ 3 ነው፦ ምዕራፉ የሚሸፍነው፣ አጭር ማስታወሻዎቹ፣ የመልመጃ ጥያቄዎች ከመልሶቻቸው ጋር፣ እና ቪዲዮ ባለበት የትምህርቱ ቪዲዮ።

4
ካርዶች: 10
የምዕራፍ 3 የመልመጃ ጥያቄዎች: 60–81
የምዕራፍ 3 የመፅሐፍ ገጾች

ምዕራፍ 3 የሚሸፍነው

1.Elasticity and plasticity
2.Density and Specific Gravity
3.Stress and Strain
4.Young's Modulus
5.Static equilibrium

የምዕራፍ 3 አጭር ማስታወሻዎች

በ10ኛ ክፍል የፊዚክስ ገጽ ላይ በዚህ ምዕራፍ ሥር የተመዘገቡት ካርዶች። አንድ በአንድ ይክፈቱ።

የስታቲክ ሚዛናዊነት ቅድመ ሁኔታዎችሕግ

መቼ እንደሚጠቀሙበት

በሚዛን ላይ ባለ እና በማይንቀሳቀስ ጠጣር አካል ላይ ያልታወቁ Force ወይም ርቀቶችን ለማስላት ይጠቀሙ።

ይጠንቀቁ

አንድ አካል ሙሉ በሙሉ በስታቲክ ሚዛን ላይ የሚሆነው የተጣራ Force ዜሮ ሲሆን እና የተጣራ Torque ዜሮ ሲሆን ብቻ ነው።

ከGrade 10 Physics፣ ገጽ 60-81 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

Specific Gravityቀመር

\text{SG} = \frac{\rho}{\rho_{\text{water}}}

\text{SG} = \frac{\rho}{\rho_{\text{water}}}

$\text{SG}$: አንጻራዊ ጥግግት $\text{dimensionless}$
$\rho$: የቁሱ ጥግግት $\text{kg}\,\text{m}^{-3}$
$\rho_{\text{water}}$: የውሃ ጥግግት $\text{kg}\,\text{m}^{-3}$

መቼ እንደሚጠቀሙበት

የአንድ ቁስ Density ከውሃ Density አንጻር ምን ያህል እጥፍ እንደሆነ ለማወቅ ይጠቀሙ።

ይጠንቀቁ

Specific gravity ንጽጽር ስለሆነ Unit የለውም። ከማካፈልዎ በፊት የሁለቱም Density መለኪያ አንድ ዓይነት መሆኑን ያረጋግጡ።

ከGrade 10 Physics፣ ገጽ 60-81 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

Torqueቀመር

\tau = F_{\perp} r

\tau = F_{\perp} r

$\tau$: ቶርክ $\text{N}\,\text{m}$
$\text{F}_{\perp}$: ቀጥተኛ ኃይል $\text{N}$
$r$: ከተዘዋዋሪው ነጥብ ያለው ርቀት $\text{m}$

መቼ እንደሚጠቀሙበት

ከ pivot ነጥብ በተወሰነ ርቀት ላይ የሚተገበር Force የሚያመጣውን የማሽከርከር አቅም ለማስላት ይጠቀሙ።

ይጠንቀቁ

ርቀት ሁልጊዜ ከ pivot ነጥብ መለካት አለበት፣ እንዲሁም የማሽከርከር አቅም የሚፈጥረው perpendicular የሆነው የ Force ክፍል ብቻ ነው።

ከGrade 10 Physics፣ ገጽ 60-81 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

Young's Modulusቀመር

Y = \frac{F L_0}{A \Delta L}

Y = \frac{F L_0}{A \Delta L}

$Y$: የያንግ ሞጁለስ $\text{N}\,\text{m}^{-2}$
$F$: የመሳብ ኃይል $\text{N}$
$L_0$: የመጀመሪያ ርዝመት $\text{m}$
$A$: የመስቀለኛ ክፍል ስፋት $\text{m}^2$
$\Delta L$: የርዝመት ለውጥ $\text{m}$

መቼ እንደሚጠቀሙበት

አንድ ጠጣር አካል በተለጣጭነት ወሰኑ ውስጥ ሲሆን የርዝመት ለውጥን፣ Tensile stress ወይም Tensile strain ለማስላት ይጠቀሙ።

ይጠንቀቁ

የሽቦው Diameter ከተሰጠ Area ሲሰላ Diameter ስኩዌር ተደርጎ ለ 4 መካፈል አለበት እንጂ Diameter ብቻውን ስኩዌር አይደረግም።

ከGrade 10 Physics፣ ገጽ 60-81 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የምዕራፍ 3 የመልመጃ ጥያቄዎች

በዚህ ምዕራፍ ላይ የተጻፉ 10 የምርጫ ጥያቄዎች፣ እያንዳንዳቸው መልሱና ምክንያቱ አላቸው። መልሱን ከመክፈትዎ በፊት ይሞክሩ። ጥያቄዎቹ በእንግሊዝኛ ናቸው።

ጥያቄ 1

What is the physical property of a solid material that allows it to return to its original shape after an applied stretching force is removed?

A.Plasticity
B.Elasticity
C.Tensile stress
D.Specific gravity

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ B Elasticity

ምክንያቱ

Elasticity is the property of a material by which it returns to its original shape and size when the applied force or load is removed.

ጥያቄ 2

During a classroom activity, a piece of brass sinks in water while a block of wood floats. Why does this happen?

A.Brass has a greater density than water, whereas wood has a lower density than water.
B.Brass has a lower density than water, whereas wood has a greater density than water.
C.Brass is elastic, whereas wood is plastic.
D.Brass has zero net force acting on it, whereas wood experiences zero torque.

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A Brass has a greater density than water, whereas wood has a lower density than water.

ምክንያቱ

An object sinks if its density is greater than the density of the liquid, and it floats if its density is lower. Brass is denser than water, while wood is less dense.

ጥያቄ 3

Which condition represents the first condition of static equilibrium for a rigid body?

A.The net torque acting on the body must be zero.
B.The net force acting on the body must be zero.
C.Stress must be directly proportional to strain.
D.The body must be stretched beyond its elastic limit.

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ B The net force acting on the body must be zero.

ምክንያቱ

The first condition of equilibrium states that the vector sum of all external forces acting on the body must be zero (net force = 0), meaning ∑F_x = 0 and ∑F_y = 0.

ጥያቄ 4

Tensile strain is calculated by dividing the change in length (ΔL) by the original length (L₀). What is the unit of tensile strain?

A.N/m^2
B.N
C.Dimensionless (it has no units)
D.kg/m^3

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ C Dimensionless (it has no units)

ምክንያቱ

Strain is a ratio of two lengths (ΔL / L₀), so the units cancel out. Therefore, strain is a dimensionless quantity.

ጥያቄ 5

A student calculates the average density of the Earth to be 5.54 × 10³ kg/m³. If the density of water is 1.0 × 10³ kg/m³, what is the specific gravity (SG) of the Earth?

A.0.18
B.2.80
C.5.54
D.55.4

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ C 5.54

ምክንያቱ

Specific gravity is the ratio of the density of a substance to the density of water: SG = ρ_Earth / ρ_water = (5.54 × 10³ kg/m³) / (1.0 × 10³ kg/m³) = 5.54.

ጥያቄ 6

A wire in a physics laboratory in Hawassa has an original length of 4.0 m. When pulled, its length increases by 0.24 mm. What is the tensile strain in the wire?

A.6.0 × 10^-5
B.9.6 × 10^-4
C.6.0 × 10^-2
D.1.67 × 10^4

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A 6.0 × 10^-5

ምክንያቱ

Convert 0.24 mm to meters: 0.24 × 10^-3 m. Then, Tensile Strain = ΔL / L₀ = (0.24 × 10^-3 m) / 4.0 m = 6.0 × 10^-5.

ጥያቄ 7

What is the maximum stress that a material can withstand while still returning to its original shape when the force is removed?

A.Young's modulus
B.Center of mass
C.Specific gravity
D.Elastic limit

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ D Elastic limit

ምክንያቱ

The elastic limit refers to the maximum value of stress for which a material shows elastic behavior. Beyond this limit, permanent plastic deformation takes place.

ጥያቄ 8

Two children balance horizontally on a seesaw. Child 1 has a mass of 26.0 kg and sits 1.60 m from the pivot. If Child 2 has a mass of 32.0 kg, at what distance from the pivot must Child 2 sit?

A.0.77 m
B.1.30 m
C.1.97 m
D.2.08 m

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ B 1.30 m

ምክንያቱ

For rotational balance, the net torque is zero: (m₁)(g)(r₁) = (m₂)(g)(r₂). Thus, r₂ = (26.0 kg × 1.60 m) / 32.0 kg = 1.30 m.

ጥያቄ 9

A wire with a cross-sectional area of 3.14 × 10^-6 m² supports a suspended mass of 2.0 kg. Using g = 9.8 N/kg, what is the tensile stress in the wire?

A.6.24 × 10^6 N/m^2
B.3.18 × 10^7 N/m^2
C.1.96 × 10^1 N/m^2
D.6.14 × 10^-7 N/m^2

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A 6.24 × 10^6 N/m^2

ምክንያቱ

Tensile stress = F / A = (mg) / A = (2.0 kg × 9.8 N/kg) / (3.14 × 10^-6 m²) = 19.6 N / (3.14 × 10^-6 m²) = 6.24 × 10⁶ N/m².

ጥያቄ 10

A person standing at the end of a board creates a torque of 1800 N·m about a support post 4.0 m away. Taking g = 9.8 N/kg, what is the mass of the person?