no i dont agree, because a glass bowl is shiny but its not a metal. just because some metals are shiny doesnt make all metals shiny
Answer:
0.191 s
Explanation:
The distance from the center of the cube to the upper corner is r = d/√2.
When the cube is rotated an angle θ, the spring is stretched a distance of r sin θ. The new vertical distance from the center to the corner is r cos θ.
Sum of the torques:
∑τ = Iα
Fr cos θ = Iα
(k r sin θ) r cos θ = Iα
kr² sin θ cos θ = Iα
k (d²/2) sin θ cos θ = Iα
For a cube rotating about its center, I = ⅙ md².
k (d²/2) sin θ cos θ = ⅙ md² α
3k sin θ cos θ = mα
3/2 k sin(2θ) = mα
For small values of θ, sin θ ≈ θ.
3/2 k (2θ) = mα
α = (3k/m) θ
d²θ/dt² = (3k/m) θ
For this differential equation, the coefficient is the square of the angular frequency, ω².
ω² = 3k/m
ω = √(3k/m)
The period is:
T = 2π / ω
T = 2π √(m/(3k))
Given m = 2.50 kg and k = 900 N/m:
T = 2π √(2.50 kg / (3 × 900 N/m))
T = 0.191 s
The period is 0.191 seconds.
Answer:
Torque decreases .
Explanation:
The tape is pulled at constant speed , speed v is constant , so there is
v = ω r where ω is angular speed and r is radius , As radius decreases , angular speed ω increases , So there is angular acceleration .
Let it be α . Let I be moment of inertia of reel .
Reel is in the form of disc
I = 1/2 m r²
I x α = torque
1/2 m r² x α = torque
As the reel is untapped , its mass decreases , r also decreases , so torques also decreases .
Answer:
16 m/s.
Explanation:
The following data were obtained from the question:
Mass of truck = 5000 Kg
Velocity of truck = 8 m/s
Mass of car = 2500 kg
Velocity of car =..?
Next, we shall determine the momentum of the truck. This can be obtained as follow:
Mass of truck = 5000 Kg
Velocity of truck = 8 m/s
Momentum of truck =.?
Momentum = mass × velocity
Momentum = 5000 × 8
Momentum of the truck = 40000 Kg.m/s
Finally, we shall determine the velocity of the car as follow:
From the question given above, we were told that the car and truck has the same momentum.
This implies that:
Momentum of the truck = momentum of car = 40000 Kg.m/s
Thus, the velocity of the car can be obtained as shown below:
Mass of car = 2500 kg
Momentum of the car = 40000 Kg.m/s
Velocity of car =..?
Momentum = mass × velocity
40000 = 2500 × velocity
Divide both side by 2500
Velocity = 40000/2500
Velocity = 16 m/s
Therefore, the velocity of the car is 16 m/s.
