Answer:
fr = 269.3 N
Explanation:
Let's use Newton's second law, for this it is good to see the attached diagram,
X axis
fr -F2 = 0
fr = F2
Y Axis
N-W = 0
We must include the rotation balance, place the rotation point at the bottom of the ladder and take the positive counterclockwise turns.
Σ τ = 0
F2 x -W y / 2 = 0
We look for x and y with trigonometry
sin 70 = y / L
cos 70 = x / L
y = L sin70
x = L cos 70
We substitute and calculate F2
F2 L cos 70 = W L sin 70 / 2
F2 = mg/2 tan 70
F2 = 20 9.8/2 tan 70
F2 = 269.3 N
From the first equation (x axis)
fr = F2
fr = 269.3 N
Potential energy is the greatest when the the kinetic energy is the least. This occurs when the ball loses the energy to fly higher, and begins to fall back to the ground.
Answer:
I already told ya
Explanation:
i got brainly so i could learn
Electrons move from the potassium atoms to the sulfur atoms.
Telescopes have three functions
1 to collect more light
2 To resolve close objects
3 To magnify.
Explanation:
To collect more light we have to build large sized mirrors..Then only we can see very faint objects.
To separate two close objects a also we need large aperture
So by making large telescopes we can see more faint objects and more deeper into universe..