<span>A fence runs all the way around the house but never moves.</span>
Answer: The drag force goes up by a factor of 4
Explanation:
The <u>Drag Force</u> equation is:
(1)
Where:
is the Drag Force
is the Drag coefficient, which depends on the material
is the density of the fluid where the bicycle is moving (<u>air in this case)
</u>
is the transversal area of the body or object
the bicycle's velocity
Now, if we assume
,
and
do not change, we can rewrite (1) as:
(2)
Where
groups all these coefficients.
So, if we have a new velocity
, which is the double of the former velocity:
(3)
Equation (2) is written as:
(4)
Comparing (2) and (4) we can conclude<u> the Drag force is four times greater when the speed is doubled.</u>
Explanation:
Acceleration is change in velocity over change in time:
a = Δv / Δt
a = (10 m/s - 25 m/s) / (240 s - 0 s)
a = -0.0625 m/s²
So the car decelerates at 0.0625 m/s².
Answer:
The aim of Watson and Rayner was to condition a phobia in an emotionally stable child.
Explanation:
Does this help?
The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
<span>
NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
</span><span>
KOH
- it is a strong base (pH=14)
</span>
↓
He needs to use HF (Hydrogen fluoride) to decrease the pH.