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2 years ago

To protect a material from the influence of an external magnetic field, the material should be kept in?

1 answer:

5 0

To protect a material from the influence of an external magnetic field, the material should be kept in soft iron ring.

So the correct answer is A.

Hope this helps,

Davinia.

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A constant 10.0-N horizontal force is applied to a 20.0-kg cart at rest on a level floor. If friction is negligible, what is the

Otrada [13]

Answer:

2.83 m/s

Explanation:

Given:

Mass of the cart (m) = 20.0 kg

Initial velocity of the cart (u) = 0 m/s

Final velocity (v) = ? m/s

Displacement of the cart (S) = 8.0 m

Horizontal force acting on the cart (F) = 10.0 N

Surface is frictionless. So, only horizontal force is the force acting on the cart.

Now, as per work-energy theorem, the work done by the net force acting on a body is equal to the change in the kinetic energy of the body.

Here, the work done by the horizontal force is given as:

$W_{net}=FS=(10\ N)(8.0\ m)=80\ Nm$

The change in kinetic energy is given as:

$\Delta K=\frac{1}{2}m(v^2-u^2)\\\\\Delta K=\frac{1}{2}(20.0\ kg)(v^2-0)\\\\\Delta K=10v^2$

Now, from work-energy theorem:

$\Delta K=W_{net}\\\\10v^2=80\\\\v^2=\frac{80}{10}\\\\v=\sqrt{8}=2.83\ m/s$

Therefore, the speed of the cart when it has been pushed 8.0 m is 2.83 m/s.

5 0

2 years ago

1. A big league hitter attacks a fastball! The ball has a mass of 0.16 kg. It is pitched at 38 m/s. After the player hits the ba

MariettaO [177]

Momentum = (mass) x (velocity)

Original momentum before the hit =

   (0.16 kg) x (38 m/s) this way <==

   =    6.08 kg-m/s this way <==

Momentum after the hit =

   (0.16) x (44 m/s) that way ==>

   = 7.04 kg-m/s that way ==>

Change in momentum = (6.08 + 7.04) = 13.12 kg-m/s that way ==> .
-----------------------------------------------

Change in momentum = impulse.

   Impulse = (force) x (time the force lasted)

13.12 kg-m/s = (force) x (0.002 sec)

(13.12 kg-m/s) / (0.002 sec) = Force

   6,560 kg-m/s² = 6,560 Newtons = Force

    ( about 1,475 pounds ! ! ! )

8 0

2 years ago

A student measured the mass of ice in a glass container with a tight lid. He allowed the ice to melt, and then found the mass of

vfiekz [6]

Answer:

The liquid formed from a melted solid has the same mass as the solid has.

Explanation:

As long as no water can escape, the mass of the ice before melting must equal the mass of the liquid water after.

7 0

2 years ago

What occurs during stage one sleep

Mekhanik [1.2K]

Answer:

Stage one of sleep, also known as the transitional phase, occurs when one finds themselves floating in and out of consciousness. During this NREM stage, you may be partially awake while your mind begins to drift off. This period of drowsiness eventually leads to a light sleep

Explanation:

i found it on google

3 0

3 years ago

The focal length of the lens of a simple digital camera is 40 mm, and it is originally focused on a person 25 m away. In what di

ss7ja [257]

Answer:

Explanation:

Here image distance is fixed .

In the first case if v be image distance

1 / v - 1 / -25 = 1 / .05

1 / v = 1 / .05 - 1 / 25

= 20 - .04 = 19.96

v = .0501 m = 5.01 cm

In the second case

u = 4 ,

1 / v - 1 / - 4 = 1 / .05

1 / v = 20 - 1 / 4 = 19.75

v = .0506 = 5.06 cm

So lens must be moved forward by 5.06 - 5.01 = .05 cm ( away from film )

3 0

3 years ago