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3 years ago

12. A boy of mass 50 kg running 5m/s jumps on to a 20kg trolley

Physics

1 answer:

atroni [7]3 years ago

7 0

Answer:

4 m/s

Explanation:

Momentum is conserved.

m₁ v₁ + m₂ v₂ = (m₁ + m₂) v

(50)(5) + (20)(1.5) = (50 + 20) v

v = 4

The final velocity is 4 m/s.

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The electric field in a region of space increases from 0 to 2150 N/C in 5.00 s. What is the magnitude of the induced magnetic fi

Feliz [49]

To solve this problem we will use the Ampere-Maxwell law, which describes the magnetic fields that result from a transmitter wire or loop in electromagnetic surveys. According to Ampere-Maxwell law:

$\oint \vec{B}\vec{dl} = \mu_0 \epsilon_0 \frac{d\Phi_E}{dt}$

Where,

B= Magnetic Field

l = length

$\mu_0$ = Vacuum permeability

$\epsilon_0$ = Vacuum permittivity

Since the change in length (dl) by which the magnetic field moves is equivalent to the perimeter of the circumference and that the electric flow is the rate of change of the electric field by the area, we have to

$B(2\pi r) = \mu_0 \epsilon_0 \frac{d(EA)}{dt}$

Recall that the speed of light is equivalent to

$c^2 = \frac{1}{\mu_0 \epsilon_0}$

Then replacing,

$B(2\pi r) = \frac{1}{C^2} (\pi r^2) \frac{d(E)}{dt}$

$B = \frac{r}{2C^2} \frac{dE}{dt}$

Our values are given as

$dE = 2150N/C$

$dt = 5s$

$C = 3*10^8m/s$

$D = 0.440m \rightarrow r = 0.220m$

Replacing we have,

$B = \frac{r}{2C^2} \frac{dE}{dt}$

$B = \frac{0.220}{2(3*10^8)^2} \frac{2150}{5}$

$B =5.25*10^{-16}T$

Therefore the magnetic field around this circular area is $B =5.25*10^{-16}T$

3 0

3 years ago

Using Mirror equation A, Calculate The Frequency Of The Long Stand And The Shortest Wave Length Of That An Object Is Placed Of A

Leya [2.2K]

The Image distance and Magnification of The Image will be 30 cm and 3.

<h3>What is focal length?</h3>

The focal length of the lens, which is often expressed in millimeters, is the distance between the lens and the image sensor when the subject is in focus.

Given data;

Focal length,f=?

Image distance,v=?

Object distance,u= 10 cm

Magnification,m= 2.85

The focal length is half of the radius;

f=R/2

f=30 Cm/2

f= 15 Cm

The mirror equation is found as;

$\rm \frac{1}{f} =\frac{1}{v} +\frac{1}{u} \\\\\ \frac{1}{15}=\frac{1}{v}+\frac{1}{10} } \\\\\ v= -30 \ cm$

The magnification of the lens is found as;

$\rm m=\frac{30}{10}\\\\ m=3$

Hence, the image distance and magnification of The image will be 30 cm and 3.

To learn more about the focal length refer;

brainly.com/question/16188698

#SPJ1

6 0

2 years ago

Picture showing four cards in a row with labels 'First animal appears on land', 'First life form appears in the sea', 'First roc

sasho [114]

The answer would be 'First rocks formed on Earth'.

3 0

3 years ago

which best describes what happens with the sonar to sound pulses from a ship after they hit the ocean floor?

lakkis [162]

Answer:

With sonar, what happens to sound pulses from a ship after they hit the ocean floor? ... They bounce back to the ship.

Explanation:

3 0

3 years ago

Help please help! Need help

Alborosie

Answer:

M. Magnetism is a property of individual atoms.

Explanation:

when a magnet is broken into pieces the new pieces behave like the original magnet this observation shows that magnetism is the property of individual atoms.

7 0

2 years ago