Need some help with this. Not sure how to go about solving it. Help is appreciat

Question

Need some help with this. Not sure how to go about solving it. Help is appreciated, please show work.

This section will allow you to do some permanent magnet DC motor calculations based on the NXT motors. If these motors are used without the encoders and operated at full speed they function as permanent magnet DC motors with approximately the following parameters: (assuming you don't include external gearing).

No Load Speed: 163 rpm

No Load Current: 60 mA

Stall Torque: 40 N?cm

Stall Current: 1.26 A

Explanation / Answer

a)

No, they are different w's. A lot of times in physics letter's are repeated because we run out so you need to be careful.

NOTE: In both cases however, it should actually be an "omega" (?) not a (w).

The first one ?=v/r is for ANGULAR VELOCITY... (I'm not yelling.. just emphasizing :D)

This is angular speed at which something rotates, or rate of change of the angle.

The second one you listed is for ANGULAR FREQUENCY.

actually it is usually written with a zero subscript as ?0 or ??, which should be read as "omega nought" (nought sounds like "not") but some people say "omega zero" which is less common.

?? is a constant of an oscillating system and has units of Hertz, like frequency.. in fact another equation for ?? is 2*pi*frequency. so it is directly proportional to frequency.

b)

Force (N)

F = m x a m = mass (kg)

a = acceleration (m/sec2)

Motor Torque (N-m)

T = F x d F = force (N)

d = moment arm (m)

Power (W)

P = I x V I = current (amps)

V = voltage (V)

P = T x ? T = torque (N-m)

? = angular velocity (rad/sec)

Unit Conversions

Length: 1 in = 0.0254 m

Velocity: 1 RPM = 0.11 rad/sec

Torque: 1 in-lb = 0.11 N-m

Power: 1 HP = 745.7 W = 550 lb-ft/sec

c)

Maximum power point tracking (MPPT) is a technique that grid connected inverters, solar battery chargers and similar devices use to get the maximum possible power from one or more photovoltaic devices, typically solar panels,[1] though optical power transmission systems can benefit from similar technology.[2] Solar cells have a complex relationship between solar irradiation, temperature and total resistance that produces a non-linear output efficiency which can be analyzed based on the I-V curve. It is the purpose of the MPPT system to sample the output of the cells and apply the proper resistance (load) to obtain maximum power for any given environmental conditions.[citation needed] MPPT devices are typically integrated into an electric power converter system that provides voltage or current conversion, filtering, and regulation for driving various loads, including power grids, batteries, or motors   

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