Answer:
D) wood rubbed against a rough surface feels hot
Explanation:
The heat is transferred from one form of energy (friction of the wood being rubbed against the surface) to another (heat energy).
Answer:
Options B, A, D, C
Explanation:
When a scientists, let's say Roberto wonders if the presence of other elements also affects the color of a flame, he can decide to prove this through a study. Therefore, in chemistry class, Roberto sees that traces of lithium makes a flame appear bright red. Subsequently, Roberto designs an experiment to test flame color in the presence of different elements and finally Roberto's friend tells him the color of a flame cannot be changed, but Roberto is still unsure.
Answer:
The curl is 
Explanation:
Given the vector function
We can calculate the curl using the definition
Thus for the exercise we will have
So we will get
Working with the partial derivatives we get the curl
Average velocity is 1..2 mi/min east
Explanation:
- Velocity = Displacement/Time
Here, displacement = 48 mi - 42 mi = 6 miles
Time = 5 minutes
⇒ Average Velocity = 6/5 = 1.2 mi/min east
