Physics Answers

You have a certain set-up of a vertical spring, and when hung freely the equilibrium position

reading is 30cm on earth. If you take the same set-up on the moon surface, would the equilibrium

position be more than, less than or equal to 30cm? Explain.

From two points each on the opposite sides of a river . The angles of elevation of the top of an 80 feet tree are 60° and 30°. The points and the tree are in the same straight line , which is perpendicular to the river. How wide is the river ?

A man 5 feet tall casts a shadow of 5 feet on the ground. Find the angle of elevation of the sun ?

Find the length of a loading ramp which extends from a building to the ground. The lower end of the ramp is 6meter from the building , and the upper is 8 meter from the building.

What is the perimeter needed to fence a right triangle with legs 63feet and 16 feet.

The lenght of a string between a kite and Point A on the ground is 442meter. If the height of the kite is 42metwr from the ground.Find the horizontal angle and distance of the kite from point A.

Lesson: Capacitance & Capacitors

Solve the problem:

The two metal objects in the figure below have net charges of +70 pC and -70 pC, which result in a 20 V potential difference between them. (a) What is the capacitance of the system? (b) if the charges are changed to +200 pC and -200pC, what does capacitance become? (c) What does the potential difference become?

Show that superposition principle does not hold for a non linear DE like; d²x/d²t + cx² = 0 where c is constant.

a force B is required to bring a box with a mass of 2.5 kg to the height of 3 m at an acceleration of 6. BY assuming it is smooth pulley system ,find the magnitude of force B 

An automobile engine has an efficiency of 20% and produces 6000 J work. Find

the heat rejected by the engine.