Answer:
a)- 1.799 rad/sec²
b)- 17.6 x 10ˉ³Nm
Explanation:
ω₀ = 720 rev/min x (1 min/60 sec) x (2π rad / 1 rev) = 24π rad/s
a) Assuming a constant angular acceleration, the formula will be
α = (ωf -ω₀) / t
As final state of the grindstone is at rest, so ωf =0
⇒ α = (0-24π) / 41.9 = - 1.799 rad/sec²
b)Moment of inertia I for a disk about its central axis
I = ½mr²
where m=2kg and radius 'r'= 0.099m
I = ½(2)(0.099²)
I = 9.8 x 10ˉ³ kgm²
Next is to determine the frictional torque exerted on the grindstone, that caused it to stop, applying the rotational equivalent of the Newton's 2nd law:
τ = I α =>(9.8 x 10ˉ³)(- 1.799)
τ = - 17.6 x 10ˉ³Nm
(The negative sign indicates that the frictional torque opposes to the rotation of the grindstone).
Answer:
The average speed of the cars is 50mph
Explanation:
Option C
Answer:
a) v² = G M R³, b) T = 2π /
, c) 
Explanation:
a) The kinetic energy is
K = ½ m v²
to find the velocity let's use Newton's second law
F = m a
acceleration is centripetal
a = v² / R
force is the universal force of attraction
F = G m M / r²
we substitute
G m M R² = m v² R
v² = G M R³
the kinetic energy is
K = ½ m G M R³
b) angular and linear velocity are related
v = w R
w = v / R
w =
w =
the angular velocity is related to the period
w = 2π / T
T = 2π / w
we substitute
T = 2π /
c) the angular moeomto is
L = m v r
L = m RA G M R³ R
L = 
Fastener because a fastener is something that connects to objects and usually can come apart but can also be permanent
The solution for the acceleration of gravity is given as
This is further explained below.
<h3>What is the
effective value of g, the acceleration of gravity, at 7900 km above the Earth's surface.?</h3>
Generally,
Mass of earth 
Radius of earth 
Gravitational const. 
height 

In conclusion, acceleration due to gravity at this point will be

for 

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