Answer:
a = √ (a_t² + a_c²)
a_t = dv / dt
, a_c = v² / r
Explanation:
In a two-dimensional movement, the acceleration can have two components, one in each axis of the movement, so the acceleration can be written as the components of the acceleration in each axis.
a = aₓ i ^ + a_y j ^
Another very common way of expressing acceleration is by creating a reference system with a parallel axis and a perpendicular axis. The axis called parallel is in the radial direction and the perpendicular axis is perpendicular to the movement, therefore the acceleration remains
a = √ (a_t² + a_c²)
where the tangential acceleration is
a_t = dv / dt
the centripetal acceleration is
a_c = v² / r
Because the sound waves are being observed by the people that are there and it is not empty as in an empty place the sound waves will come back to you.
Answer:
(a) 
(b) 
Explanation:
According to the law of conservation of momentum:
Initially, the girl and the plank are at rest. So, relative to the ice, we have:
(a) The velocity of the girl relative to the ice is:
Here, 
is the velocity of the girl relative to the plank and 
is the velocity of the plank relative to the ice.
Replacing (1) in (2):
(b) According to (2), the velocity of the plank relative to the surface of ice is:
The negative sing indicates that the plank is moving to the left.
