Answer:
option A
Explanation:
given,
For exerted by the worker = 245 N
angle made with horizontal = 55°
we need to calculate Force which is not used to move the crate = ?
Movement of crate is due to the horizontal component of the force.
Crate will not move due to vertical force acting on the it.



hence, worker's force not used to move the crate is equal to 200.69
The correct answer is option A
Answer:
If a man starts running on a boat with an acceleration a with respect to the boat, there is no external force that acts on the Boat+Man system
"Circulatory system" does that, as all about transportation of blood within the body comes under it's work
Hope this helps!
As the boulder falls off the cliff, the gravitational potential energy that the boulder has is converted into kinetic energy. If you do the calculations, you will see that the kinetic energy the boulder has is equal to the gravitational potential energy it had before it fell off a cliff.