Answer:
B. A object in motion stays in motion, and an object at rest stays at rest unless acted upon by a net force.
Answer:
a) T = 1,467 s
, b) A = 0.495 m
, c) v = 4.97 10⁻² m / s
Explanation:
The simple harmonic movement is described by the expression
x = A cos (wt + Ф)
Where the angular velocity is
w = √ k / m
a) Ask the period
Angular velocity, frequency and period are related
w = 2π f = 2π / T
T = 2π / w
T = 2pi √ m / k
T = 2π √ (1.2 / 22)
T = 1,467 s
f = 1 / T
f = 0.68 Hz
b) ask the amplitude
The mechanical energy of a harmonic oscillator
E = ½ k A²
A = √2 E / k
A = √ (2 2.7 / 22)
A = 0.495 m
c) the mass changes to 8.0 kg
As released from rest Ф = 0, the equation remains
x = A cos wt
w = √ (22/8)
w = 1,658
x = 3.0 cos (1,658 t)
Speed is
v = dx / dt
v = -A w sin wt
The speed is maximum when without wt = ±1
v = Aw
v = 0.03 1,658
v = 4.97 10⁻² m / s
Answer:
Explanation:
a) ωp = 2π radians / 1.7 s = <u>3.7 rad/s</u>
b) ωs = 3.7 rad/s(9.5 cm / 4.5 cm) = 7.8 rad/s
v = (ωs)R = 7.8(65) = 507 cm/s or <u>5.1 m/s</u>
c) ωs = 3.5 m/s / 0.65 m = 5.38 rad/s
ωp = 5.38(4.5 cm / 9.5 cm) = 2.55 rad/s
t = θ/ω = 2π / 2.55 = 2.463... <u>2.5 s</u>
Wow ! This is not simple. At first, it looks like there's not enough information, because we don't know the mass of the cars. But I"m pretty sure it turns out that we don't need to know it.
At the top of the first hill, the car's potential energy is
PE = (mass) x (gravity) x (height) .
At the bottom, the car's kinetic energy is
KE = (1/2) (mass) (speed²) .
You said that the car's speed is 70 m/s at the bottom of the hill,
and you also said that 10% of the energy will be lost on the way
down. So now, here comes the big jump. Put a comment under
my answer if you don't see where I got this equation:
KE = 0.9 PE
(1/2) (mass) (70 m/s)² = (0.9) (mass) (gravity) (height)
Divide each side by (mass):
(0.5) (4900 m²/s²) = (0.9) (9.8 m/s²) (height)
(There goes the mass. As long as the whole thing is 90% efficient,
the solution will be the same for any number of cars, loaded with
any number of passengers.)
Divide each side by (0.9):
(0.5/0.9) (4900 m²/s²) = (9.8 m/s²) (height)
Divide each side by (9.8 m/s²):
Height = (5/9)(4900 m²/s²) / (9.8 m/s²)
= (5 x 4900 m²/s²) / (9 x 9.8 m/s²)
= (24,500 / 88.2) (m²/s²) / (m/s²)
= 277-7/9 meters
(about 911 feet)
At the given erro in angle, the error in the measurement of sin 90 degrees would be 0.001.
<h3>
Percentage error</h3>
The percentage error of any measurement is obtained from the ratio of the error to the actual measurement.
The error of sin 90 degrees is calculated as follows;
sin 90 = 1
error in measurement = sin(90 - 0.5)
error in measurement = sin(89.5) = 0.999
<h3>Error in sin 90 degrees</h3>
Error in sin 90 degrees = 1 - 0.999
Error in sin 90 degrees = 0.001
Thus, at the given erro in angle, the error in sin 90 degrees would be 0.001.
Learn more about error in measurement here: brainly.com/question/26668346
