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2 years ago

What can Lisa do to increase the strength of the electromagnet?

Physics

1 answer:

drek231 [11]2 years ago

4 0

Answer:

move the wire loops closer

Explanation:

because the closer t they are the more concentrated the energy is in that specific area

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A 2.5-kg ball and a 5.0-kg ball have an elastic collision. Before the collision, the 2.5-kg ball was at rest and the other ball

lesantik [10]

The kinetic energy of 2.5 kg ball after collision is 27.09 J.

Answer:

Explanation:

In elastic collision, the sum of momentum of the objects before collision will be equal to the sum of momentum of the objects after collision.

We know that momentum is the product of mass and velocity acting on any object.

So, the conservation of energy in elastic collision leads to following equation:

$M_{1} u_{1} +M_{2} u_{2}=M_{1} v_{1}+M_{2} v_{2}$

Since, the momentum is conserved ,the kinetic energy will also be conserved in elastic collision. So

$M_{1} u_{1} ^{2}+M_{2} u_{2} ^{2}=M_{1}v_{1} ^{2}+ M_{2}v_{2} ^{2}$

Since initial velocity for M1 ball is zero, then

$M_{2} u_{2}=M_{1} v_{1}+M_{2} v_{2}$

and

$M_{2} u_{2} ^{2}=M_{1}v_{1} ^{2}+ M_{2}v_{2} ^{2}$

So, on solving all the above equation, we get an equation for velocity and that is

$\frac{2M_{2}u_{2} }{(M_{1}+M_{2} }$ =final velocity of ball with mass 2.5 kg

$v = \frac{2(5*3.5)}{2.5+5}=4.67 m/s$

So kinetic energy will be 1/2 mv2

Kinetic energy of 2.5 kg ball is $\frac{1}{2}*2.5*(4.67)^{2} =27.09 J$

So the kinetic energy of 2.5 kg ball after collision is 27.09 J.

6 0

3 years ago

Ml(d^2θ/dt^2) =-mgθ

Nata [24]

The equation of motion of a pendulum is:

$\dfrac{\textrm{d}^2\theta}{\textrm{d}t^2} = -\dfrac{g}{\ell}\sin\theta,$

where $\ell$ it its length and $g$ is the gravitational acceleration. Notice that the mass is absent from the equation! This is quite hard to solve, but for <em>small</em> angles ( $\theta \ll 1$ ), we can use:

$\sin\theta \simeq \theta.$

Additionally, let us define:

$\omega^2\equiv\dfrac{g}{\ell}.$

We can now write:

$\dfrac{\textrm{d}^2\theta}{\textrm{d}t^2} = -\omega^2\theta.$

The solution to this differential equation is:

$\theta(t) = A\sin(\omega t + \phi),$

where $A$ and $\phi$ are constants to be determined using the initial conditions. Notice that they will not have any influence on the period, since it is given simply by:

$T = \dfrac{2\pi}{\omega} = 2\pi\sqrt{\dfrac{g}{\ell}}.$

This justifies that the period depends only on the pendulum's length.

4 0

3 years ago

A flat disk, a solid sphere, and a hollow sphere each have the same mass m and radius r. The three objects are arranged so that

chubhunter [2.5K]

Answer:

Explanation:The rotational inertia of any object depends directly on the distance the mass is from the axis of a rotating object

Having more mass at the sides will increase the rotational inertia of the object that is why a Hollow sphere having same M and R as the solid one has more rotational inertia as it has more mass at the sides.

The sphere have some mass at the center but most of its mass is closer to its radius and thus have more inertia than flat Disk.

The same relation exist between a flat disk and hollow sphere. The hollow sphere have some mass at the center but most of its mass is closer to its radius and thus have more inertia.

The rotational of the objects can be calculated by these equations

$FlatDisk=\frac{1}{4} MR^2\\Sphere=\frac{2}{5} MR^2\\HollowSphere=\frac{2}{3} MR^2\\$

4 0

2 years ago

jeremie ran around the track at the ymca for 2 hours. when he was done he figured that he had traveled 20 kilometers. what was h

laila [671]

(1) Speed is the ratio of the total distance covered by the object and the total time it takes for him to finish it.

Speed = distance / time

In this item, we are given that the distance is 20 kilometers and that the time it takes for the trip is 2 hours. Substituting the known values,
Speed = 20 kilometers / 2 hours
speed = 20 km/h

(2) Velocity on the other hand takes into account the displacement of the object from his original position. It is assumed that Jeremie was basically back to his original position after two hours. Hence, the velocity is equal to zero.

3 0

2 years ago

A radioactive isotope has a life for 15 minutes. It has an initial count rate of 36000 Bg. What will the count be after 1 hour?

lukranit [14]

Answer:

18000 Bg

Explanation:

after 15 minutes = 36000/2

After 30 minutes = 36000/4

30 minutes × 2 = 1 hour

After 1 hour = 36000/4 × 2 = 18000 Bg

3 0

2 years ago