Answer:
Shortest time = 58.18 × 10^(-6) s
Explanation:
We are given;
s(x,t) = 5.00 nm cos((60.00 m^(−1)x) − (18.00 X 10³ s^(−1)t))
Let us set x = 0 as origin.
Now, for us to find the time difference, we need to solve 2 equations which are;
s(x,t) = 5.00 nm cos((60.00 m^(−1)x) − (18.00 X 10³ s^(−1)t1))
And
s(x,t) = 5.00 nm cos((60.00 m^(−1)x) − (18.00 X 10³ s^(−1)t2))
Now, since the wave starts from maxima at time at t = 0, the required time would be the difference (t2 - t1)
Thus, the solutions are;
t1 = (1/(18 × 10³)) cos^(-1) (2.5/5)
And
t2 = (1/(18 × 10³)) cos^(-1) (-2.5/5)
Angle of the cos function is in radians, thus;
t1 = 58.18 × 10^(-6) s
t2 = 116.36 × 10^(-6) s
So,
Required time = t2 - t1 = (116.36 × 10^(-6) s) - (58.18 × 10^(-6) s) = 58.18 × 10^(-6) s
We have: A= F.s
So, A = 22 x 16
A= 352J
Só A is correct answer
Answer:
Explanation:
The first thing to have to make a diagram where we indicate the forces acting on the block, see attached. We have the following
The weight (W) that is vertical
The friction force (fr) that opposes the movement
The driving force (F)
The normal (N) which is the reaction to the support of the body and is perpendicular to the surface
We write a reference system where one axis is parallel to the surface (x axis) and the other is perpendicular to it (Y axis) we decompose the forces on these axes, we see that the only force we have to decompose r is the weight
sin θ = Wx / W ⇒ Wx = W sin θ
cos θ = Xy / W ⇒ Wy = Wcos θ
We write Newton's equations for each axis
N- Wy = 0
F -fr -Wx = m a (1)
The expression for the friction force is
fr = μ N
N = Wy
N = W cos θ
fr = μ mg cosT
We hope, we simplify the acceleration of equation 1
a = F - μ mg cos θ -mg sinθ
a = F - mg (μ cos θ -sin θ)
This is the general equation for movement.
Answer:
block is being held in place on a frictionless surface. The block has a mass of 3.9 kg and is held in place on an incline of angle = 32° by a horizontal force F, as shown in the figure below.
Explanation:
When Kevin pulls off this stunt, his average speed is (distance) / (time).
So, whatever the distance may be, his average speed for the trip is
(some distance)/0 = infinite speed.
Now, stay with me here:
His acceleration at the beginning of the trip is
(change in speed) / (time to change)
Whatever speed he started at, his acceleration had to be
(infinite change in speed)/(no time).
That's a big acceleration doncha know.
He needed an infinite force and an infinite amount of energy from somewhere to achieve that acceleration, and as soon as he started accelerating, his insides got totally shredded.
Whatever arrived on Planet-Y looked like a pile of overcooked pasta.
It wasn't worth the trip.
