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
The choice of path should make no difference. The work should depend only on the end points and not on the route between them. But just to make sure, could we please have a look at the accompanying figure ?
<h2>Olivia is on a Swing at Playground - Option 2 </h2>
Olivia is on a swing at the playground. Her kinetic energy increasing at x and her potential energy decreasing at x. At mean position velocity is maximum so kinetic energy ( K.E ) is also maximum and at mean position potential energy is minimum. Therefore, kinetic energy is increasing and potential energy decreasing at x.
Answer:
The velocity of a ball will be "-70.13 m/s".
Explanation:
The given values are:
u = 70 m
t = 0.0 s
g = a = -9.8 m/s²
s = -1 m
v = ?
As we know,
The equation of motion will be:
⇒
On substituting the estimated values, we get
⇒
⇒
⇒
⇒
⇒
⇒
In downward direction, it will be:
⇒
As the sphere moves in the liquid, it experiences a viscous force upwards that tries to resist its downward motion caused by gravity(it's own weight). This viscous force gradually increases with depth, as the speed rises(because the weight causes a positive acceleration in it's direction). At a point, the viscous force upwards becomes exactly equal to the weight downwards. Then the sphere reaches equilibrium. It doesn't have any external force acting on it, so it can't have any acceleration. So, it's velocity becomes constant, and this velocity is known as the terminal velocity.