Answer:
a) 1.06*10^-5
b) 0.00105 °C^-1
Explanation:
Given that
Length of the cylinder, L = 1.5 m
Radius of the cylinder, r = 0.25 cm
Voltage across the rod, V = 15 V
I• at Temperature T• = 20° C is 18.5 A
I at Temperature T = 90° C is 17.2 A
See attachment for calculations
Answer: B
Explanation:the voltage is just like the force that drives the current through out the circui... When trippled, the force increases and the current increases since the resistance in the circuit remains constant.
Answer:
A. absorb heat energy and move farther apart
Explanation:
The answer is A since when a ice cube takes in heat, it changes form and melts down to a liquid : water.
The molecules in water are farther apart since they are moving around alot but can be contained in a container.
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.
PM me for full answer, please. If it's not too late.