A piece of copper has a volume of 100.0 cm³. If the mass is 890 g, what is the density of copper

A child in a boat throws a 5.80-kg package out horizontally with a speed of 10.0 m/s. The mass of the child is 24.6kg and the ma

Sergio [31]

Answer:

-0.912 m/s

Explanation:

When the package is thrown out, momentum is conserved. The total momentum after is the same as the total momentum before, which is 0, since the boat was initially at rest.

$(m_c + m_b)v_b + m_pv_p = 0$

where $m_c = 24.6 kg, m_b = 39 kg, m_p = 5.8 kg$ are the mass of the child, the boat and the package, respectively. $, v_p = 10m/s, v_b$ are the velocity of the package and the boat after throwing.

$(24.6 + 39)v_b + 5.8*10 = 0$

$63.6v_b + 58 = 0$

$v_b = -58/63.6 = -0.912 m/s$

3 0

3 years ago

A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

____ [38]

At the highest point in its trajectory, the ball's acceleration is zero but its velocity is not zero.

<h3>What's the velocity of the ball at the highest point of the trajectory?</h3>

At the highest point, the ball doesn't go more high. So its vertical velocity is zero.
However, the ball moves horizontal, so its horizontal component of velocity is non - zero i.e. u×cosθ.
u= initial velocity, θ= angle of projection

<h3>What's the acceleration of the ball at the highest point of projectile?</h3>

During the whole projectile motion, the earth exerts the gravitational force with a acceleration of gravity along vertical direction.
But as there's no acceleration along vertical direction, so the acceleration along vertical direction is zero.

Thus, we can conclude that the acceleration is zero and velocity is non-zero at the highest point projectile motion.

Disclaimer: The question was given incomplete on the portal. Here is the complete question.

Question: Player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

A- neither the ball's velocity nor its acceleration are zero.

B- the ball's acceleration points upward.

C- the ball's acceleration is zero but its velocity is not zero.

D- the ball's velocity points downward.

Learn more about the projectile motion here:

brainly.com/question/24216590

#SPJ1

7 0

2 years ago

An AC generator consists of 20 circular loops of wire with an area of 75 cm2. It has a maximum induced voltage of 24 V. If its a

Monica [59]

Faraday's law allows us to find the magnetic field that produces the emf in the rotating system is:

The magnetic field is: B = 0.424 T

Faraday's law of induction states that when the magnetic flux changes in time, an induced electromotive force is produced.

fem = $- \frac{d \Phi_B }{dt}$

where fem is the induced electromotive force and Ф the flux,

The magnetic flux is the scalar product of the field and the area.

$\Phi_B = B . A = B A \ cos \theta$

In this case we have several turns, so the expression remains.

fem = $- N B A \ \frac{d cos \theta}{dt}$

Indicate that the turns rotate at a constant frequency, therefore we can use the uniform rotational motion ratio.

θ = w t

We substitute

$fem = - N B A \ \frac{d \ cos \ wt}{dt}\\fem = N B A w sin \ wt$

the maximum induced electromotive force occurs when the sine function is ±1

fem = N B A w

They indicate that the fem = 24 V, the number of the turn is N = 20, the area is A = 75 cm² = 75 10⁻⁴ m² and the frequency f = 60 Hz

Frequency and angular velocity are related.

w = 2π f

We substitute.

fem = N B A 2π f

$B = \frac{fem }{2 \pi \ NA \ f}$

Let's calculate.

$B= \frac{24 }{2\pi \ 20 \ 75 \ 10^{-4} 60}$ B = 24 / 2pi 20 75 10-4 60

B = 0.424 T

In conclusion, using Faraday's law we can find the magnetic field that produces the emf in the rotating system is:

The magnetic field is; B = 0.424 T

Learn more about Faraday's law here: brainly.com/question/24617581

8 0

2 years ago

Two coils of wire are placed close together. Initially, a current of 3.04 A exists in one of the coils, but there is no current

Alchen [17]

Answer:

$M=0.0247H$

Explanation:

Given data

$V_{voltage}=4.29V\\I_{current}=3.04A\\t_{time}=1.75*10^{-2}s$

To find

Mutual inductance of the two-coil system

Solution

The mutual inductance given as:

M= (-VΔt)/ΔI

Substitute the given values

So

$M=-\frac{4.29V*1.75*10^{-2}s}{(0-3.04A)}\\ M=0.0247H$

4 0

3 years ago

Water _____.

Mice21 [21]

Water expands when it freezes (that's why you should never put closed, fully filled water bottles in the freezer !)

6 0

3 years ago

Read 2 more answers