change of an object relative to the position of another object.
There is need 4.5 hours to fill the pool in case if both pipes are open
Answer:

Explanation:
Given
-- Mass of the boy
-- Mass of the girl
-- Acceleration of the girl towards the boy
Required
Determine the acceleration of the boy towards the girl (
)
From the question, we understand that the surface is frictionless. This implies that the system is internal and the relationship between the given and required parameters is:

Substitute values for
and 

Make
the subject




<em>Hence, the acceleration of the boy towards the girl is 1.446m/s^2</em>
Answer:
when the pencil is balanced on a point it is motionless due to net force only acting trough the center, but when we release the position we are changing the location of a pencil hence due to turning affect it will expericence torque and the angular acceleration produced.
for the complete answer the length and mass of pencil should be known i am giving the general expression for the calculation of angular acceleration
Explanation:
<h3>τ=Iα</h3><h3>τ= torque</h3><h3>I = inertia</h3><h3>α= angular acceleration</h3>
where
I= mL^2/3 (by geometry of pencil)
when the pencil is released it will experience force due to weight
F=mgsinθ
so τ=Fxd
τ=mgsin(10°)x(L/2)
then.
α=τ/I
α=mgsin(10°)xL/2÷(mL^2)/3
To solve this problem we will apply the principle of conservation of energy. For this purpose, potential energy is equivalent to kinetic energy, and this clearly depends on the position of the body. In turn, we also note that the height traveled is twice that of the rigid rod, therefore applying these concepts we will have





Therefore the minimum speed at the bottom is required to make the ball go over the top of the circle is 4.67m/s