Answer:
the maximum possible constant speed is 8 m/sec
Explanation:
from the image, Given that
r(t) = (2t, t²,t²/3), -5 ≤ t ≤ 5
Given that the curvature K(t) = 2 / ( t² + 2)²
note that t² + 2 ≥ 2
(t² + 2)² ≥ 4
1 / (t² + 2)² ≤ 1/4
2 / (t² + 2)² ≤ 1/2
Also note that k(0) = 1/2
The normal component of acceleration satisfies aN = kv²
where v = ║v(t)║is the speed of the roller coaster.
The maximum possible normal component of acceleration is 32
so, aN ≤ 32 every where on the track
aN = kv² ≤ 1/2v² ≤ 32
v² ≤ 64
Therefore, the maximum possible constant speed is 8 m/sec
The flow of electricity in a certain path is the circuit.
Answer:
μsmín = 0.1
Explanation:
- There are three external forces acting on the riders, two in the vertical direction that oppose each other, the force due to gravity (which we call weight) and the friction force.
- This friction force has a maximum value, that can be written as follows:
where μs is the coefficient of static friction, and Fn is the normal force,
perpendicular to the wall and aiming to the center of rotation.
- This force is the only force acting in the horizontal direction, but, at the same time, is the force that keeps the riders rotating, which is the centripetal force.
- This force has the following general expression:
where ω is the angular velocity of the riders, and r the distance to the
center of rotation (the radius of the circle), and m the mass of the
riders.
Since Fc is actually Fn, we can replace the right side of (2) in (1), as
follows:
- When the riders are on the verge of sliding down, this force must be equal to the weight Fg, so we can write the following equation:
- (The coefficient of static friction is the minimum possible, due to any value less than it would cause the riders to slide down)
- Cancelling the masses on both sides of (4), we get:
- Prior to solve (5) we need to convert ω from rev/min to rad/sec, as follows:
- Replacing by the givens in (5), we can solve for μsmín, as follows:
Answer:
The law of inertia
Explanation:
A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force
Answer:
The rock will reach 9 m from the ground at eaxactly 5.06 s after it was initially thrown upwards.
Explanation:
We will use the equations of motion for this.
u = initial velocity of the rock = 22 m/s
g = acceleration due to gravity = -9.8 m/s²
y = vertical position of the rock at a time t = 9 m
y₀ = initial height of the rock = 25 m
t = time it takes for the rock to reach height of 9 m.
(y-y₀) = ut + 0.5gt²
(9 - 25) = 22t + 0.5(-9.8)t²
- 14 = 22t - 4.9t²
4.9t² - 22t - 14 = 0
solving this quadratic equation,
t = 5.055 s or - 0.565 s
Since time cannot be negative,
t = 5.055 s = 5.06 s
Hope this Helps!!!