|acceleration| = (change in speed) / (time for the change)
= (10 m/s - 0) / (4 s)
= (10 / 4) (m/s²)
= 2.5 m/s² .
The direction of the acceleration is west.
Answer:
a) C.M 
b) 
Explanation:
The center of mass "represent the unique point in an object or system which can be used to describe the system's response to external forces and torques"
The center of mass on a two dimensional plane is defined with the following formulas:


Where M represent the sum of all the masses on the system.
And the center of mass C.M 
Part a
represent the masses.
represent the coordinates for the masses with the units on meters.
So we have everything in order to find the center of mass, if we begin with the x coordinate we have:


C.M 
Part b
For this case we have an additional mass
and we know that the resulting new center of mass it at the origin C.M
and we want to find the location for this new particle. Let the coordinates for this new particle given by (a,b)

If we solve for a we got:




And solving for b we got:

So the coordinates for this new particle are:

they are heated to extremely high temperatures. they are cooled to extremely low temperatures. they are made to be very thick.
Explanation:
The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis. As a result, the moon does not seem to be spinning but appears to observers from Earth to be keeping almost perfectly still. Scientists call this synchronous rotation
To determine, the final velocity we use one kinematic equation. It would be 2ax = vf^2 - v0^2. The initial velocity would be zero since it starts from rest. Therefore, the equation would be:
vf = √(2ax) where a is the acceleration ( a = g ) and x is the height
vf = √(2)(9.8)(25)
vf = - 22.14 m/s