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. September 2017

Rotational Motion

Q- A torque of 50 N.m accelerates a wheel from rest to 100 rev/min in 5 seconds.

(a) What is the angular displacement of the wheel in 5 second?

(b) What is the angular acceleration of the wheel?

(c) What is the moment of inertia of the wheel?

Solution:

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Magnetic Effects: Force on a particle

Q- A charged particle (q = +3.5 µC) moves at speed v0 = 55 m/s in the +x-direction. At x = 0 it enters a region where a uniform magnetic field B = 2.5 T directed in the +z direction.

(a) What is the magnitude of the magnetic force on the particle? 

(b) What electric field can make the net forc…

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Work, Power and Energy

Q- A skier of mass 70 kg is pulled up a slope by a motor driven cable.

(a) How much work is required to pull him 60 m up the 300 slope (assumed friction-less) at a constant speed of 2.0 m/s?

(b) What power must the motor have to perform this task? 

Solution:

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Gravitation: Acceleration Due To Gravity

Q- Calculate the acceleration due to gravity at a height of 8.848 km from surface of the earth.

Solution:

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Modern Physics: Radioactivity

Q- A drug tagged with a radioactive tracer (half life = 6.05 hours) is prepared for a patient.

(a) What is the decay constant for the radioactive tracer?

(b) If the initial mass of the radioactive tracer is 1g, what mass of it will remain after 24 hours?

Solution:

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Waves

Q- Figure shows a snapshot graph of a wave traveling to the right along a string at 55 m/s. Each interval on the vertical axis corresponds to 0.5 cm. At this instant, what is the velocity of points 1, 2, and 3 on the string?

Solution:

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Electromagnetic Induction

Q-A one-turn rectangular loop oriented parallel to the x-y plane and having dimensions a = 2 cm, b = 11 cm moves with a constant velocity v = 20 m/s in the +x direction. An external agent (force) ensures that this velocity remains constant throughout the motion. The wire of which the loop is made ha…

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Rotational Motion

Q- A wheel starting from rest with uniform angular acceleration makes 3 revolutions in 8 s

(a) What is the angular acceleration of the wheel?

(b) What is its angular velocity at t = 8 s?

(c) What is the linear speed of a particle at distance 0.50 m from the axis of rotation at t = 8 s?

Solution:

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Ray Optics: Concave Lens

Q- A double concave lens of index of refraction 1.45 has radii of magnitudes 31 cm and 21 cm. An object is located 80 cm to the left of the lens. Find the following-

(a) The focal length of the lens

(b)  The location of the image

(c) The magnification of the image

(d) Describe the image.

Solut…

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Newton's Laws of Motion

Q- A man claims that as long as he has his seat belt on, he can hold on to a 12.0 kg child in a 60.0 mi/h head on collision with a brick wall in which the car passenger compartment comes to a stop in 0.050 s. Is his claim true? Explain why he will experience a violent force during the collision, tea…

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