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BlackZzzverrR [31]
2 years ago
12

As the motor speeds up, the value of current decreases because of A. Friction loss B. Increase in resistance C. Increase in back

emf D. All mentioned above
Physics
1 answer:
Thepotemich [5.8K]2 years ago
6 0

Answer:

C. Increase in back emf

Explanation:

As the current through the field winding decreases the field strength also decreases and the back-emf is reduced, as a result the motor speeds up.

When the motor begins to speed-up, an additional back EMF is generated due to induction which reduces armature current. This also results in reduced strength of the field flux. The back emf generated is not enough to reduce the armature current which could stop the acceleration of the motor and the motor further accelerates.

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A current of 5.0 a flows through an electrical device for 10 seconds. how many electrons flow through this device during this ti
melisa1 [442]
1 Amp = 1 Coulomb/sec
1 Coulomb/sec = 6.25*10^18 electrons/sec

Therefore,
5.0 A = 5 C/s = 5*6.25*10^18 = 3.125*10^19 e/s

In 10 second, number of electrons are calculated as;
Number of electrons through the device = 3.125*10^19*10 = 3.125*10^20 electrons

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3 years ago
If I keep F constant in F=ma, what is the relationship between m and a?
Jobisdone [24]

Answer:

If F is a constant, we can take f = 1

f = m×a

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2 years ago
Study the roller coaster diagram. Match the labels to the correct location on the roller coaster.
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Answer:

A- Greatest Kinetic Energy

B- Increasing Potential Energy

C- Increasing Kinetic Energy

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Explanation:

hope this is right.

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2 years ago
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Discuss why Wolpert says we have a brain.
ycow [4]

Answer:

“We have a brain for one reason and one reason only, and that's to produce adaptable and complex movements,” stated Wolpert, Director of the Computational and Biological Learning Lab at the University of Cambridge. ... The evidence for this is in how well we've learned to mimic our movements using computers and robots.

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510 g squirrel with a surface area of 935 cm2 falls from a 4.8-m tree to the ground. Estimate its terminal velocity. (Use the dr
Yuki888 [10]

Answer:

The terminal velocity is v_t  =17.5 \ m/s

Explanation:

From the question we are told that

       The mass of the squirrel is  m_s  =  50\ g  =  \frac{50}{1000} =  0.05 \  kg

      The surface area is   A_s =  935 cm^2  =  \frac{935}{10000} = 0.0935 \ m^2

       The height of fall is  h =4.8 m

        The length of the prism is l =  23.2 = 0.232 \ m

          The width of the prism is w =  11.6 =  0.116 \ m

 

The terminal velocity is mathematically represented as

       v_t  =  \sqrt{\frac{2 * m_s *  g }{\dho_s * C  * A } }

Where \rho  is the density of a rectangular prism with a constant values of \rho  =  1.21 \ kg/m^3

            C is the drag coefficient for a horizontal skydiver with a value = 1

            A  is the area of the prism the squirrel is assumed to be which is mathematically represented as

      A =  0.116 * 0.232

       A =  0.026912 \ m^2

 substituting values

      v_t  =  \sqrt{\frac{2 * 0.510 *  9.8 }{1.21 * 1  * 0.026912 } }

     v_t  =17.5 \ m/s

       

7 0
3 years ago
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