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#angular speed

32 public questions tagged with this topic.

A torque of 25Nm acts on a wheel with moment of inertia 5kg m2 starting from rest. What is its angular speed after 2s?

α = τI = 255 = 5rad/s2. ω = ω0+αt = 0+5×2 = 10rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 10 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A thin ring of mass 1kg and radius 0.4m has a kinetic energy of 8J. What is its angular speed?

I = MR2 = 1×(0.4)2 = 0.16kg m2. K = 12Iω2⇒8 = 12×0.16×ω2⇒16 = 0.16ω2⇒ω2 = 100⇒ω = 10rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 10 rad/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A hollow cylinder of mass 1kg and radius 0.2m has a kinetic energy of 2J. What is its angular speed?

I = MR2 = 1×(0.2)2 = 0.04kg m2. K = 12Iω2⇒2 = 12×0.04×ω2⇒4 = 0.04ω2⇒ω2 = 100⇒ω = 10rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 10 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A solid cylinder of mass 2kg and radius 0.5m has a kinetic energy of 10J. What is its angular speed?

I = 12MR2 = 12×2×(0.5)2 = 0.25kg m2. K = 12Iω2⇒10 = 12×0.25×ω2⇒20 = 0.25ω2⇒ω2 = 80⇒ω = 80≈8.94rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 8.94 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A uniform disk of mass 2kg and radius 0.2m rotates about its center with an angular speed of 10rad/s. What is its rotati

Rotational KE: K = 12Iω2. Moment of inertia of a disk: I = 12MR2 = 12×2×(0.2)2 = 0.04kg m2. K = 12×0.04×(10)2 = 0.02×100 = 2J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 2 J. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A solid sphere of mass 1kg and radius 0.8m has a kinetic energy of 12.8J. What is its angular speed?

I = 25MR2 = 25×1×(0.8)2 = 0.256kg m2. K = 12Iω2⇒12.8 = 12×0.256×ω2⇒25.6 = 0.256ω2⇒ω2 = 100⇒ω = 10rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 10 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A thin ring of mass 1kg and radius 0.2m rotates about its center. If its kinetic energy is 4J, what is its angular speed

KE: K = 12Iω2. For a ring: I = MR2 = 1×(0.2)2 = 0.04kg m2. 4 = 12×0.04×ω2⇒8 = 0.04ω2⇒ω2 = 200⇒ω = 200≈14.14rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 14 rad/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A hollow cylinder of mass 5kg and radius 0.2m rotates about its axis at 10rad/s. What is its rotational kinetic energy?

I = MR2 = 5×(0.2)2 = 0.2kg m2. K = 12Iω2 = 12×0.2×(10)2 = 0.1×100 = 10J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 10 J. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A torque of 18Nm acts on a disk with moment of inertia 6kg m2 starting from rest. What is its angular speed after 4s?

α = τI = 186 = 3rad/s2. ω = ω0+αt = 0+3×4 = 12rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 12 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A torque of 15Nm acts on a wheel with moment of inertia 5kg m2 starting from rest. What is its angular speed after 3s?

α = τI = 155 = 3rad/s2. ω = ω0+αt = 0+3×3 = 9rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 9 rad/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.