Answer:
A) α = -1.228 rev/min²
B) 7980 revolutions
C) α_t = -8.57 x 10^(-4) m/s²
D) α = 21.5 m/s²
Explanation:
A) Using first equation of motion, we have;
ω = ω_o + αt
Where,
ω_o is initial angular velocity
α is angular acceleration
t is time the flywheel take to slow down to rest.
We are given, ω_o = 140 rev/min ; t = 1.9 hours = 1.9 x 60 seconds = 114 s ; ω = 0 rev/min
Thus,
0 = 140 + 114α
α = -140/114
α = -1.228 rev/min²
B) the number of revolutions would be given by the equation of motion;
S = (ω_o)t + (1/2)αt²
S = 140(114) - (1/2)(1.228)(114)²
S ≈ 7980 revolutions
C) we want to find tangential component of the velocity with r = 40cm = 0.4m
We will need to convert the angular acceleration to rad/s²
Thus,
α = -1.228 x (2π/60²) = - 0.0021433 rad/s²
Now, formula for tangential acceleration is;
α_t = α x r
α_t = - 0.0021433 x 0.4
α_t = -8.57 x 10^(-4) m/s²
D) we are told that the angular velocity is now 70 rev/min.
Let's convert it to rad/s;
ω = 70 x (2π/60) = 7.33 rad/s
So, radial angular acceleration is;
α_r = ω²r = 7.33² x 0.4
α_r = 21.49 m/s²
Thus, magnitude of total linear acceleration is;
α = √((α_t)² + (α_r)²)
α = √((-8.57 x 10^(-4))² + (21.49)²)
α = √461.82
α = 21.5 m/s²
Answer:
73.8 N
Explanation:
The total volume is,
V =
=
= 0.1396 m
The average density is,
=
= 7.169 g/cm³
The linear mass density is,
μ = pπr²
= (7.169 x 10⁹) (π (0.3 x 10⁻³)²)
= 2.026 x 10⁻³ Kg/m
The fundamental mode of length is,
L = λ/2
λ=2L
= 2 x 0.65
= 1.3 m
The speed of the wave is,
v = λf
= 1.3 m x 147 Hz
= 1.91 m/s
The tension is,
v = √T/ц
T = ц v²
= 2.026 x 10⁻³)(1.91 m/s)²
= 73.769N
73.8N
Answer:
They both rises to same height.
Explanation:
When an object is sliding up in friction less surface than according to conservation of energy its potential energy will be converted into kinetic energy.
Here, m is the mass, v is the velocity, g is the acceleration due to gravity and H is the height.
Here the height is independent on the mass of an object and its only depend on velocity.
Now according to the question, two objects have same velocity but they have different masses.
Therefore, they rises to the same height because height will not change with mass.
Let's recall Kinetic Energy Formula as follows:
Ek = Kinetic Energy ( Joule )
m = mass of the object ( kg )
v = speed of the object ( m/s )
Let us now tackle the problem !
Given:
initial speed of first object = initial speed of second object = v
final speed of first object = final speed of second object = 0
mass of first object = m
mass of second object = 2m
Asked:
height = H = ?
Solution:
We will use Conservation of Energy to solve this problem:
Both objects rise to the same height
Grade: High School
Subject: Physics
Chapter: Energy
Answer:
acceleration for time interval from 1 sec to 4 second is 1.5 metre/second^2
mark it as brainliest!!
magnitude of Alpha Crucis is 0.77. Identify which star appears brighter when observed from
Earth. Explain your answer.
Answer:
Alpha centauri will be brighter than Alpha Crucis .
Explanation:
Apparent magnitude of a star measures how bright a star is .
This scale is reverse logarithmic ie , the brighter the star , the lower is its magnitude . A magnitude equal to 5 scale higher represents less magnitude by a factor of 1/ 100 . In this way a difference of 1 magnitude represents a brightness ratio of 2.512 . Hence a star of brightness magnitude of 7 is less bright by a factor 2.512 than that of a star magnitude of 6 .