Answer:
T = 120.3 N
Explanation:
Since, the tension in the rope is acting against both the centripetal force and the weight of the stone. As both act downward towards center of the circle and tension acts towards point of support that is upward. So, tension will be equal to the sum of centripetal force and weight of the stone:
Tension = Centripetal Force + Weight of Stone
T = mv²/r + mg
where,
m = mass of stone = 5.31 kg
r = radius of circle = length of string = 2.99 m
g = 9.8 m/s²
Therefore,
T = (5.31 kg)(6.2 m/s)²/(2.99 m) + (5.31 kg)(9.8 m/s²)
T = 68.27 N + 52.03 N
<u>T = 120.3 N</u>
That's efficiency. There's no law that it must be stated in percent.
Answer:
0.832
Explanation:
8.320 x 10 to the negative 1st power is 0.832
C. meter per second
Velocity and speed share the same SI unit.
Answer:
a) w = 4.24 rad / s
, b) α = 8.99 rad / s²
Explanation:
a) For this exercise we use the conservation of kinetic energy,
Initial. Vertical bar
Emo = U = m g h
Final. Just before touching the floor
Emf = K = ½ I w2
As there is no friction the mechanical energy is conserved
Emo = emf
mgh = ½ m w²
The moment of inertial of a point mass is
I = m L²
m g h = ½ (m L²) w²
w = √ 2gh / L²
The initial height h when the bar is vertical is equal to the length of the bar
h = L
w = √ 2g / L
Let's calculate
w = RA (2 9.8 / 1.09)
w = 4.24 rad / s
b) Let's use Newton's equation for rotational motion
τ = I α
F L = (m L²) α
The force applied is the weight of the object, which is at a distance L from the point of gro
mg L = m L² α
α = g / L
α = 9.8 / 1.09
α = 8.99 rad / s²
