Solve the following roblems. (9.) A crow bar of length 2 m is used to lift a stone of weight 200 kg. If the fulcrum is set 50 cm apart from the stone, how much effort should be applied to the other end of the crowbar to balance it? ​

Sorry my friend i don't know the answer. i am just in 6th

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.