Answer:
a) 2.18 m/s^2
b) 9.83 m/s
Explanation:
The flywheel has a moment of inertia
J = m * k^2
Where
J: moment of inertia
k: radius of gyration
In this case:
J = 144 * 0.45^2 = 29.2 kg*m^2
The block is attached through a wire that is wrapped around the wheel. The weight of the block causes a torque.
T = p * r
r is the radius of the wheel.
T = m1 * g * r
T = 18 * 9.81 * 0.6 = 106 N*m
The torque will cause an acceleration on the flywheel:
T = J * γ
γ = T/J
γ = 106/29.2 = 3.63 rad/s^2
SInce the block is attached to the wheel the acceleration of the block is the same as the tangential acceleration at the eddge of the wheel:
at = γ * r
at = 3.63 * 0.6 = 2.81 m/s^2
Now that we know the acceleration of the block we can forget about the flywheel.
The equation for uniformly accelerated movement is:
X(t) = X0 + V0*t + 1/2*a*t^2
We can set a frame of reference that has X0 = 0, V0 = 0 and the X axis points in the direction the block will move. Then:
X(t) = 1/2*a*t^2
Rearranging
t^2 = 2*X(t)/a
It will reach the 1.8 m in 3.6 s.
Now we use the equation for speed under constant acceleration:
V(t) = V0 + a*t
V(3.6) = 2.81 * 3.6 = 9.83 m/s
Answer:
The entity relationship (ER) data model has existed for over 35 years. It is well suited to data modelling for use with databases because it is fairly abstract and is easy to discuss and explain. ER models are readily translated to relations. ER models, also called an ER schema, are represented by ER diagrams.
Answer:
15.4 g/cm³, 17.4 g/cm³
Explanation:
The densities can be calculated using the formula below
ρ = (fraction of tungsten × ρt ( density of tungsten)) + (fraction of pores × ρp( density of pore)
fraction of tungsten = (100 - 20 ) % = 80 / 100 = 0.8
a) density of the before infiltration = ( 0.8 × 19.25) + (0.2 × 0) = 15.4 g/cm³
b) density after infiltration with silver
fraction occupied by silver = 20 / 100 = 0.2
density after infiltration with silver = ( 0.8 × 19.25) + (0.2 × 10) = 17.4 g/cm³
Answer:
Both technician A and B
Explanation:
Passive permanent magnet ABS wheel speed sensors produce an A/C voltage signal. Wheel speed sensors are a necessary ABS component and sensor input. It is used to inform the ABS control module of rotational wheel speed. A passive sensor creates an AC signal that changes frequency as the wheel changes speed. Moreover, input from wheel speed sensors are used for anti-
lock brake, electronic traction control, and electronic stability control systems. Therefore, both technicians are correct.
Answer:
Kinetic energy can be used to develop electric energy which can be used as electricity.
Explanation:
The kinetic energy can be harnessed; much like some hydro power technologies harness water movement. A way to convert this kinetic energy into electric energy is through piezoelectric. By applying a mechanical stress to a piezoelectric crystal or material an electric current will be created and can be harvested.
Kinetic energy is also generated by the human body when it is in motion. Studies have also been done using kinetic energy and then converting it to other types of energy, which is then used to power everything from flashlights to radios and more.
