What is a force, motion and energy??
2 answers:
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Answer:
θ = 28°
Explanation:
For this exercise We will use the second law and Newton, let's set a System of horizontal and vertical.
X axis
Fₓ = m a
Nₓ = m a
Where the acceleration is centripetal
a = v² / r
The only force that we must decompose is normal, let's use trigonometry
sin θ = Nₓ / N
cos θ = / N
Nₓ = N sin θ
= N cos θ
Let's replace
N sin θ = m v² / r
Y Axis
- W = 0
N cos θ = mg
Let's divide the two equations of Newton's second law
Sin θ / cos θ = v² / g r
tan θ = v² / g r
θ = tan⁻¹ (v² / g r)
We reduce the speed to the SI system
v = 61 km / h (1000 m / 1 km) (1h / 3600 s) = 16.94 m / s
Let's calculate
θ = tan⁻¹ (16.94 2 / (9.8 55.1)
θ = tan⁻¹ (0.5317)
θ = 28°
Answer: D. The force and displacement are in the same direction.
Explanation:
The Work done by a Force
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path with distance
.
Work is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy).
Now, when the applied force is constant and the direction of the force and the direction of the displacement are <u>parallel</u>, the equation to calculate it is:
(1)
When they are not parallel, both directions form an angle, let's call it . In that case the expression to calculate the Work is:
(2)
When the force and displacement are perpendicular to each other, and <u>no work is done</u>.