If dirt and grease were good conductors of electrical current, then we could make wire
out of dirt and grease instead of expensive copper. Sadly, they're not. So a coating of
dirt and grease on the wire can have a substantial impact on the connection, and can
even block the flow of current across the connection completely. Moreover, in the case
where the ends of the wires are to be soldered, solder does not adhere to dirty wire.
Weight of the carriage 
Normal force 
Frictional force 
Acceleration 
Explanation:
We have to look into the FBD of the carriage.
Horizontal forces and Vertical forces separately.
To calculate Weight we know that both the mass of the baby and the carriage will be added.
- So Weight(W)
To calculate normal force we have to look upon the vertical component of forces, as Normal force is acting vertically.We have weight which is a downward force along with 
, force of 
acting vertically downward.Both are downward and Normal is upward so Normal force 
- Normal force (N)
- Frictional force (f)
To calculate acceleration we will use Newtons second law.
That is Force is product of mass and acceleration.
We can see in the diagram that 
and 
component of forces.
So Fnet = Fy(Horizontal) - f(friction) 
- Acceleration (a) =
So we have the weight of the carriage, normal force,frictional force and acceleration.
Answer:
answer a, 4
Explanation:
when the 4 is before the compound it applies to the whole compound
Answer:f^n=m(a+g)
Explanation:khan academy said
Answer:
442.5 rad
Explanation:
w₀ = initial angular velocity of the disk = 7.0 rad/s
α = Constant angular acceleration = 3.0 rad/s²
t = time period of rotation of the disk = 15 s
θ = angular displacement of the point on the rim
Angular displacement of the point on the rim is given as
θ = w₀ t + (0.5) α t²
inserting the values
θ = (7.0) (15) + (0.5) (3.0) (15)²
θ = 442.5 rad
