Answer:
Explanation:
Hello,
Let's get the data for this question before proceeding to solve the problems.
Mass of flywheel = 40kg
Speed of flywheel = 590rpm
Diameter = 75cm , radius = diameter/ 2 = 75 / 2 = 37.5cm.
Time = 30s = 0.5 min
During the power off, the flywheel made 230 complete revolutions.
∇θ = [(ω₂ + ω₁) / 2] × t
∇θ = [(590 + ω₂) / 2] × 0.5
But ∇θ = 230 revolutions
∇θ/t = (530 + ω₂) / 2
230 / 0.5 = (530 + ω₂) / 2
Solve for ω₂
460 = 295 + 0.5ω₂
ω₂ = 330rpm
a)
ω₂ = ω₁ + αt
but α = ?
α = (ω₂ - ω₁) / t
α = (330 - 590) / 0.5
α = -260 / 0.5
α = -520rev/min
b)
ω₂ = ω₁ + αt
0 = 590 +(-520)t
520t = 590
solve for t
t = 590 / 520
t = 1.13min
60 seconds = 1min
X seconds = 1.13min
x = (60 × 1.13) / 1
x = 68seconds
∇θ = [(ω₂ + ω₁) / 2] × t
∇θ = [(590 + 0) / 2] × 1.13
∇θ = 333.35 rev/min
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force.
I hope this helped! If so, please mark brainliest!
The buoyant force on the lead balloon was caused by the air molecules in the room and thus these air molecules will be hitting the surface of the balloon and those collisions will cause a force per unit area.
Answer: Option D
<u>Explanation:
</u>
The term buoyant force is exerted mostly by objects getting fully or partially immersed in a fluid. This is the upward thrusting force exerted by the fluid on the bottom of the object to prevent the complete immersion of the object.
In other words, the buoyant force helps to keep the object floating. In case of balloon in air, the air pressure acts as the fluid which will be hitting the surface of balloon.
So, these collisions will prevent the balloon to fall down and to remain floating in air with an upward push from the collision of air molecules with the surface of balloon. So, the buoyant force acts on the lead balloon by collision of air molecules with the surface of balloon and pushing it in upward direction.
