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4 years ago

What is an electric motor? Explain its operation.

2 answers:

7 0

An electric motor is an electrical machine that converts electrical energy into mechanical energy.

Electric motors work on the principal of the interaction between magnetic field electr-magnetism. A loop which is carrying the current is placed in a magnetic field. The loop will experience a torque. The torque starts rotating the coil and the propellers start to rotate when the current passes through the loop.

qwelly [4]4 years ago

4 0

Answer:

(Straight out of Physics textbook)

Explanation:

An electric motor is a slightly modified galvanometer. An electric motor current changes direction every time the coil makes a half revolution. Electric motors have greatly impacted the way of life. It made it possible to replace enormous human and animal toil by electric power all over the world.

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In certain cases, using both the momentum principle and energy principle to analyze a system is useful, as they each can reveal

SpyIntel [72]

Answer:

A) F_g = 26284.48 N

B) v = 7404.18 m/s

C) E = 19.19 × 10^(10) J

Explanation:

We are given;

Mass of satellite; m = 3500 kg

Mass of the earth; M = 6 x 10²⁴ Kg

Earth circular orbit radius; R = 7.3 x 10⁶ m

A) Formula for the gravitational force is;

F_g = GmM/r²

Where G is gravitational constant = 6.67 × 10^(-11) N.m²/kg²

Plugging in the relevant values, we have;

F_g = (6.67 × 10^(-11) × 3500 × 6 x 10²⁴)/(7.3 x 10⁶)²

F_g = 26284.48 N

B) From the momentum principle, we have that the gravitational force is equal to the centripetal force.

Thus;

GmM/r² = mv²/r

Making v th subject, we have;

v = √(GM/r)

Plugging in the relevant values;

v = √(6.67 × 10^(-11) × 6 x 10²⁴)/(7.3 x 10⁶))

v = 7404.18 m/s

C) From the energy principle, the minimum amount of work is given by;

E = (GmM/r) - ½mv²

Plugging in the relevant values;

E = [(6.67 × 10^(-11) × 3500 × 6 × 10²⁴)/(7.3 x 10⁶)] - (½ × 3500 × 7404.18)

E = 19.19 × 10^(10) J

5 0

3 years ago

Complete the ray diagram below:

s2008m [1.1K]

Answer:inverted, real, and same size

Explanation:

6 0

3 years ago

A 1.7 kg model airplane is flying north at 12.5 m/s initially, and 25 seconds later is observed heading 30 degrees west of north

maxonik [38]

Answer:

Average net force = 0.62 N

Explanation:

We are given;

Mass; m = 1.7 kg

Initial velocity; u = 12.5 m/s

Final velocity; v = 25 m/s

time; t = 25 seconds

Now, we are told that the final velocity was 30° west of North. So, resolving this velocity along the horizontal gives;

v = 25 cos 30°

Now, using Newton's first equation of motion gives;

v = u + at

Where a is acceleration

Plugging in the relevant values gives;

25 cos 30° = 12.5 + 25a

21.6506 - 12.5 = 25a

a = (21.6506 - 12.5)/25

a = 0.3660 m/s²

Now, magnitude of the average net force would be; F = ma

F = 1.7 × 0.366

F ≈ 0.62 N

5 0

4 years ago

Q 6: A body throws a ball vertically up. It returns to the ground after 5 seconds. Find

Rasek [7]

Answer:

Taking gravity to be 9.8m/s2, The velocity is 24.5m/s2.

Taking gravity to be 10m/s2, The velocity is 25m/s2.

Explanation:

According the first formula of motion under the influence of gravity for upward motion, v=u-gt, where v=final velocity, u=initial velocity, and t= time taken.

Here the time taken for the ball to reach the maximum point is half of 5, which is 2.5 seconds.

And v is 0, since at the maximum point gravity slows down the velocity to 0.

Finding the initial velocity,

v=u-gt

0=u-10(2.5)

u=10(2.5)

u=25m/s

8 0

3 years ago

Once you have pulled hard enough to start the box moving upward, what is the magnitude F of the upward force you must apply to t

Brrunno [24]

Answer:

F = mg/2

Explanation:

The full question is attached to the solution of this question.

The forces acting on the box include the weight of the box, the force, F and the tension in the wire attached.

The force required to pull up the box at constant velocity normally is equal to the weight of the box.

W = mg

But in this setup,

The force balance on the box

Sum of upward forces = sum of downward forces.

T + F = mg

But the pulley is frictionless, hence, the force, F is equal to the tension in the wire.

T = F

2F = mg

F = mg/2

Hope this Helps!!!

8 0

3 years ago