Since you are just trying to find the vertical acceleration and not the horizontal acceleration, angle and velocity do not come into play in this problem. The downward pull of gravity has a vertical acceleration of 9.8 m/s/s, which would be your answer.
When you're dealing with projectile problems, you have two dimensions: an x (horizontal) dimension and a y (vertical) dimension. The only force that will be acting upon a projectile in the air is the force of gravity, which points down in the y/vertical dimension.
Gravity causes a downward vertical acceleration of . The velocity and angle do not affect the vertical acceleration.
The "Ideal Mechanical advantage" (IMA) of given pulley is .
Ideal Mechanical advantage of a system is defined by the ratio of achieved or output force to the implied force. In the pulley system above, output force is the resistant force denoted by . The input force is analogous or equivalent to the effort applied i.e. .
Hence by dividing these two forces we calculate the IMA of the above mentioned pulley system which is .
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. The input force is analogous or equivalent to the effort applied i.e.
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