Mechanics questions | form five Physics

1. Why the value of acceleration due to gravity (g) changes due to the change in latitude? Give two reasons.
2. A rocket is fired from the earth towards the sun. At what point on its path is the gravitational force on the rocket zero?

Answer / Solution

UNSOLVED

1. Define torque and give its S.I. unit.
2. A disc of moment of inertia 2.5×10^-4​ kgm² ​ is rotating freely about an axis through its centre at 20​ rev/min. If some wax of mass 0.04​ kg is dropped gently on to the disc 0.05​ m from its axis, what will be the new revolution per minute of the disc?

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UNSOLVED

Explain briefly why a:

1. high diver can turn more somersaults before striking the water?
2. dancer on skates can spin faster by folding her arms?

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UNSOLVED

A heavy flywheel of moment of inertia 0.4​ kgm ​ 2 is mounted on a horizontal axle of radius 0.01​ m . ​ If a force of 60​ N ​ is applied tangentially to the axle:

1. Calculate the angular velocity of the flywheel after 5 seconds from rest.
2. List down two assumptions taken to arrive at your answer in (i).

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UNSOLVED

1. list down two main assumptions in deriving the equation of projectile motion.
2. Why the horizontal motion of a projectile is constant?

Answer / Solution

UNSOLVED