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. January 2016

Collision-Relative motion

Q- A cart (m1 = 120 kg) is moving to the right along a track at v1i = 15 m/s when it hits a stationary cart (m2 = 360 kg) and rebounds with a speed of v1f = 7 m/s in the opposite direction.

  1. With what speed does the 360 kg cart move after the collision?
  2. An observer moves in the same direction…

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NLM - Circular Motion

Q- A 3.05 kg object is attached to a vertical rod by two strings as shown in Figure. The object rotates in a horizontal circle at constant speed 6.75 m/s.

(a) Find the tension in the upper string.

(b) Find the tension in the lower string.

Solution

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Current density

Q1- Suppose a current of I = 1 A flows through a conductor that is tapered. The initial diameter of the conductor is 1 mm with a length of 5 mm. The final diameter of the conductor is 3 mm with a length of 8 mm, the tapered section in between is 10 mm long. (a) What is the current density through al…

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Capacitors

Q1- A capacitor is made from two hollow, coaxial iron cylinders, one inside the other. The inner cylinder is negatively charged and the outer is positively charged; the magnitude of the charge on each is 10.0 pC. The inner cylinder has a radius of 0.200 mm , the outer one has a radius of 5.40 mm, an…

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Rotetional Motion

A compound gear system driving a large roller is shown below.

(a)  Calculate the angular velocities of gears B, C and the product roller for when gear A has an angular velocity of 200 rpm.

(b)  When power is applied to the gear A it is required that the design running speed (of 200 rpm at…

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WPE

Q1- A girl pulls a box of mass m = 6 kg across a floor with a constant horizontal force F = 35 N. Initially the block is at rest. For the first d1 = 7 m, there is no friction between the box and the floor. For the next d2 = 7 m the coefficient of friction between the box and the floor is m = 0.1.

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Gravitation

(a) A space explorer comes across a spherical planet with a small moon in orbit around it. He observes that the moon completes one full orbit every 33 Earth days and moves at a distance R = 390 million m from the center of the planet. What is the mass of the planet? (One earth day =86400 s)

(b) U…

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Circular Motion

Q1- A car moving at a speed of 35 m/s enters a curve that describes a quarter turn of radius 125 m. The driver gently applies the brakes, giving a constant tangential deceleration of magnitude 1.2 m/s2.

a) Just before emerging from the turn, what is the magnitude of the car's acceleration?

b) …

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Projectile Motion

Projectile Motion
Q 1 - A man standing 29 m from the base of a vertical cliff throws a ball with a speed of 38 m/s aimed directly at a point 6 m above the base of the cliff.
a) How long does it take the ball to reach the cliff?
b) Neglecting air resistance and the height of the man, calculate the…

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WPE Mometntum

Question 1 - A massless spring of spring constant 20 N/m is placed between two carts. Cart 1 has a mass M1 = 5 kg and Cart 2 has a mass M2 = 3.5 kg. The carts are pushed toward one another until the spring is compressed a distance 1.4 m. The carts are then released and the spring pushes them apart. …

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