A ladder 9 m long rest at an angle of 60" to the horizontal against a smooth vertical
wall. Calculate the frictional force and the
normal force of the ground if the ladder
has a mass of 25 kg and its center of
gravity is one-third way up from the
bottom of the ladder. Use g = 9.8ms-2

Will you chech and finish these for me, because i am stumped with them.

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped