Answer:

Explanation:
R = Horizontal range of projectile = 75 m
v = Velocity of projectile = 37 m/s
g = Acceleration due to gravity = 
Horizontal range is given by

The angle at which the arrow is to be released is
.
Answer:
0.000001 kg
Explanation:
because 1 kg equal 1,000,000 milligrams
we take
which equals 0.000001 kg
as well.
1. Correct
Explanation
An inclined plane is a flat surface which lie at an angle, Its one end is higher than the other this inclined plane is used as an aid for raising or lowering a load. Staircase also work in similar manner
2. Correct
Explanation
yes all simple machine have a fulcrum
3. Incorrect
Explanation
when we swim that time our arms and legs 'push' the water due to which water displaced in backward direction so her we applied a positive work on the water. According to Newton's Third Law,same magnitude of work is done by water in opposite direction to push us back on our arms and legs. therefore water also does positive work on us.
4. incorrect
Explanation
The force exerted by a machine on an object is input force
5. Incorrect
Explanation
when the input force is greater than the output force that time machine have mechanical advantage of less than 1.