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2 years ago

Say what main energy change

Physics

1 answer:

Anit [1.1K]2 years ago

8 0

Answer:

b) boy kicking a football

Explanation:

it 's because the ball was at rest but when it was kicked, it starts to more

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A device that changes mechanical energy to electrical energy by rotating a coil of wire through a magnetic field is called a(an)

tigry1 [53]

A device that changes mechanical energy to electrical energy by rotatin a coil of wire through a magnetic field is called B. Generator

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3 years ago

Read 2 more answers

A student sits on a pivoted stool while holding a pair of weights. The stool is free to rotate about a vertical axis with neglig

Blababa [14]

Answer:

<u>Please Mark As Brainliest!!</u>

a) 4.99 rad/sec b) 6.24 rad/sec c) 7.03 J

Explanation:

a) If the student completes one turn in 1.26 sec, this is called the period of the movement.

If we take into account that the angle rotated during one turn is 2π rads, by definition of angular velocity, we can get this value as follows:

ω = Δθ / Δt = 2*π rad / 1.26 seg = 4.99 rad/sec.

b) As no external torques are acting on the system, the total angular momentum must be conserved, so we can write the following equation:

Li = Lf ⇒ I₁ * ω₁ = I₂* ω₂

So, we can solve for ω₂, as follows:

ω₂ = (I₁ * ω₁) / I₂ = 6.24 rad/sec

c) Appying the work-energy theorem, we know that the work done by the student, must be equal to the change in the kinetic energy, which in this case is only rotational, so we can write:

W = 1/2 I₂* ω₂² - 1/2 I₁ ω₁²

W =1/2 ((2.25 kg.m² * (6.24)²) (rad/sec)² - (1.8 kg.m²* (4.99)²) (rad/sec)²)

W = 7.03 J

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2 years ago

A wrench 0.500 m long is applied to a nut with a force of 80.0 N. Because of the cramped space, the force must be exerted upward

riadik2000 [5.3K]

Answer:

Torque, $\tau=34.6\ N.m$

Explanation:

It is given that,

Length of the wrench, l = 0.5 m

Force acting on the wrench, F = 80 N

The force is acting upward at an angle of 60.0° with respect to a line from the bolt through the end of the wrench. We need to find the torque is applied to the nut. We know that torque acting on an object is equal to the cross product of force and distance. It is given by :

$\tau=Fr\ sin\theta$

$\tau=80\times 0.5\ sin(60)$

$\tau=34.6\ N.m$

So, the torque is applied to the nut is 34.6 N.m. Hence, this is the required solution.

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3 years ago

1) the strength of an electromagnet can be increased by

miss Akunina [59]

Using coils of fewer turns on the electromagnet

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3 years ago

Any four function of health post

lesantik [10]

Answer:

1. be the first line of treatment for minor health conditions

2.be the first line of assessment and decision making for further diagnosis and/or treatment and for referral to a higher level facility

3. be a center for all public health activities, such as outreach ...

4. provide basic health services to people who live in rural areas.

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2 years ago