Answer:
a) Acceleration is zero
, c) Speed is cero
Explanation:
a) the equation that governs the simple harmonic motion is
x = A cos (wt +φφ)
Where A is the amplitude of the movement, w is the angular velocity and φ the initial phase determined by the initial condition
Body acceleration is
a = d²x / dt²
Let's look for the derivatives
dx / dt = - A w sin (wt + φ)
a = d²x / dt² = - A w² cos (wt + φ)
In the instant when it is not stretched x = 0
As the spring is released at maximum elongation, φ = 0
0 = A cos wt
Cos wt = 0 wt = π / 2
Acceleration is valid for this angle
a = -A w² cos π/2 = 0
Acceleration is zero
b)
c) When the spring is compressed x = A
Speed is
v = dx / dt
v = - A w sin wt
We look for time
A = A cos wt
cos wt = 1 wt = 0, π
For this time the speedy vouchers
v = -A w sin 0 = 0
Speed is cero
Im saying a or b but i pick B
Answer:
3.422 m/s^2
Explanation:
A useful relation is ...
v2^2 -v1^2 = 2ad
(25 m/s)^2 -(3 m/s)^2 = 2a(90 m)
(616 m^2/s^2)/(180 m) = a ≈ 3.422 m/s^2
The acceleration is about 3.422 m/s^2.
Answer:
The coefficient of kinetic friction is 1.03
Explanation:
<u>Step 1:</u> Given data
⇒ mass of the block = 0.600 kg
⇒ elastic constant k = 20 N/m
⇒ The spring is compressed by 20.0 cm (=x) = 0.2 m
⇒ Once it loses contact with the spring, the block travels a distance 33 cm
<u>Step 2:</u> Calculate the potential energy
Ep = 1/2 * k * x²
Ep = 1/2 * 20N/m * (0.2m)²
Ep = 0.4 Nm
<u>Step 3:</u> Calculate the coefficient of kinetic friction
At the end of the movement Potential energy = work
W = Ep = 0.4Nm = µx * m * g* x
µx = Ep / (m*g*x)
µx = 2Nm / ( 0.6 kg * 9.81 m/s² * 0.33m)
µx = 1.03
The coefficient of kinetic friction is 1.03
Answer:
8.5
Explanation:
to find efficiency take the ratio between the output and input
85/100=output/input