A metre rule is pivoted at its mid-point with a vertical force of 10N hanging from the distance 30cm from the mid-point. At what distance must a 15N force hang to balance the ruler horizontally?
A projectile is fired from the ground level with a velocity of 300ms-1 at an angle of a 30o to the horizontal.
Calculate the time taken to reach the maximum height?
[g = 10ms-2]