Answer:

Explanation:
Since, Alex is at rest. Therefore, the speed measured by him will be the absolute speed of car P. Therefore, taking easterly direction as positive:
And the absolute velocity of Barbara's Car is given as:
Now, for the velocity of Car p with respect to the velocity of Barbara's Car can be given s follows:


To find the ratio of planetary speeds Va/Vb we need the orbital velocity formula:
V=√({G*M}/R), where G is the gravitational constant, M is the mass of the distant star and R is the distance of the planet from the star it is orbiting.
So Va/Vb=[√( {G*M}/Ra) ] / [√( {G*M}/Rb) ], in our case Ra = 7.8*Rb
Va/Vb=[ √( {G*M}/{7.8*Rb} ) ] / [√( {G*M}/Rb )], we put everything under one square root by the rule: (√a) / (√b) = √(a/b)
Va/Vb=√ [ { (G*M)/(7.8*Rb) } / { (G*M)/(Rb) } ], when we cancel out G, M and Rb we get:
Va/Vb=√(1/7.8)/(1/1)=√(1/7.8)=0.358 so the ratio of Va/Vb = 0.358.
Answer:
Is to add all forces, for example either the gf = gravitational force
Ff= force fiction
Fn= normal force
Thus, fg + ff + fn = y will give you results
Well then the forces you use in your exercises or questions.
Answer:
The effect of gravity on object makes objects stable and not floating in the air . It also makes any object thrown up to return back
By the use of Ohm's law, the resistance of the bulb is 121 ohms
<h3>What is electrical power?</h3>
Let us recall that power is the rate of doing work. Now we know that the voltage of the power source is 110-V and the power is 100-W.
Since;
P= IV
I = P/V
I = 100/110
I = 0.91 A
Again;
V= IR
R = V/I
R = 110/0.91
R = 121 ohms
Learn more about resistance: brainly.com/question/11431009