On reversing the direction of the current in a wire, the magnetic field produced by it gets .....
When a body is placed on a table top, it exerts a force equal to its weight downward on the table top but does not move or fall.
i) Name the force exerted on the table top.
ii) What is the direction of the force?
How is work done by a force measured when the force:
i) is in the direction of displacement
i) Work done by a force when the force is in the direction of displacement.
That is equal to Force x Displacement of the point of application of the force in the direction of force.
ii) Work done by a force when the force is at an angle θ to the direction of displacement ,
= Force x component of displacement in the direction of force.
= Force x d cosθ
State the energy changes in the following while in use:
i) Burning of a candle
ii) A steam engine