Explanation:
Assuming the wall is frictionless, there are four forces acting on the ladder.
Weight pulling down at the center of the ladder (mg).
Reaction force pushing to the left at the wall (Rw).
Reaction force pushing up at the foot of the ladder (Rf).
Friction force pushing to the right at the foot of the ladder (Ff).
(a) Calculate the reaction force at the wall.
Take the sum of the moments about the foot of the ladder.
∑τ = Iα
Rw (3.0 sin 60°) − mg (1.5 cos 60°) = 0
Rw (3.0 sin 60°) = mg (1.5 cos 60°)
Rw = mg / (2 tan 60°)
Rw = (10 kg) (9.8 m/s²) / (2√3)
Rw = 28 N
(b) State the friction at the foot of the ladder.
Take the sum of the forces in the x direction.
∑F = ma
Ff − Rw = 0
Ff = Rw
Ff = 28 N
(c) State the reaction at the foot of the ladder.
Take the sum of the forces in the y direction.
∑F = ma
Rf − mg = 0
Rf = mg
Rf = 98 N
The displacement of the train after 2.23 seconds is 25.4 m.
<h3>
Resultant velocity of the train</h3>
The resultant velocity of the train is calculated as follows;
R² = vi² + vf² - 2vivf cos(θ)
where;
- θ is the angle between the velocity = (90 - 51) + 37 = 76⁰
R² = 8.81² + 9.66² - 2(8.81 x 9.66) cos(76)
R² = 129.75
R = √129.75
R = 11.39 m/s
<h3>Displacement of the train</h3>
Δx = vt
Δx = 11.39 m/s x 2.23 s
Δx = 25.4 m
Thus, the displacement of the train after 2.23 seconds is 25.4 m.
Learn more about displacement here: brainly.com/question/2109763
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Answer:
Explanation:
From the exercise we have that
<em><u>To find how far from the edge of the piano does the cat strike the floor, we need to calculate its time first </u></em>
At the end of the motion y=0m
Solving for t
or 
Since the <u>time</u> can't be negative the answer is t=0.73
Knowing that we can calculate how far does the cat strike the floor
We are given
E = <span>2.64 × 10-21 J
h = </span><span>6.6 × 10-34 J s
The options given below are frequencies, therefore, the question must be asking about the frequency fo the given wave
The equation is
E = h f
Simply substitute and solve for f which is the frequency
f = </span>2.64 × 10-21 J / 6.6 × 10-34 J s
f = <span>4.00 × 1012<span> hertz</span></span>
