Answer:
minimum speed v=
Explanation:
Recall the formula for centripetal force;
Centripetal force is the force that is required to keep an object moving in circular part

where;
F=centripetal force
m=mass of object
r=radius of curvature
v= minimum speed
To find minimum speed make v the subject of formula;
v=
Work = (force) x (distance)
You could look at the two cases, and see right away that
the first one has more force acting through more distance,
so it must be more work. But since I just gave you the formula
for Work, let's calculate the amount of it for both cases:
First case: Work = (115 N) x (15 m) = 1,725 joules
Second case: Work = (20 N) x (10 m) = 200 joules
The first case involves 8.625 times as much work as the second case.
<u>Answer</u>
3 Ohms
<u>Explanation</u>
when the resistors are in series, the resistance in the circuit increases. For example, if two resistors, R1 and R2 are in series, the combined resistance is R1+R2.
When connected in parallel, the total resistance is the reciprocal of (1/R1 + 1/R2)
In this case the resistors are in parallel.
Total resistance = (1/12 + 1/4)⁻¹
= (1/3)⁻¹
= 3 Ohms