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3 years ago

Why are electromagnets more useful than permanent magnets in many

Physics

2 answers:

Likurg_2 [28]3 years ago

5 0

Answer: Electromagnets can be turned on and off by controlling the current

Explanation:

Tasya [4]3 years ago

5 0

B. By controlling the current, electromagnets can be turned on and off

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the pull of gravity on mars is 3.7m/s^2. if a astronaut on mars lifts a 10 kg rock 1 m off the ground, just to see whats under i

Elanso [62]

Gravitational potential energy can be calculated using the formula:

$PE_{grav} =mgh$

Where:
PEgrav = Gravitational potential energy
m= mass
g = acceleration due to gravity
h = height

On Earth acceleration due to gravity is a constant 9.8 but since the scenario is on Mars, the pull of gravity is different. In this case, it is 3.7, so we will use that for g.

So put in what you know and solve for what you don't know.
m = 10kg
g = 3.7m/s^2
h = 1m

So we put that in and solve it.
$PE_{grav} =mgh$
$PE_{grav} =(10kg)(3.7m/s^{2})(1m)$
$PE_{grav} =37J$

7 0

4 years ago

harge of uniform density (100 nC/m3) is distributed throughout a hollow cylindrical region formed by two coaxial cylindrical sur

Elden [556K]

Answer:

The magnitude of the electric field is 8.47 N/C

Explanation:

Given;

uniform charge density, λ = 100 nC/m³

inner radii of the cylinder, r = 1.0 mm and 3.0 mm

distance from the symmetry axis, R = 2.0 mm

$Volume =\pi (R^2 -r^2)l\\\\Volume =\pi ((2*10^{-3})^2 -(1*10^{-3})^2)l\\\\Volume =\pi (4*10^{-6} - 1*10^{-6})l\\\\Volume = 3*10^{-6} \pi l \ m^3$

Area = 2πrl

Area =2π(2 x 10⁻)l

Volume = A x d

d = Volume / Area

$d = \frac{V}{A} = \frac{3*10^{-6}*\pi*l}{4\pi *10^{-3} l} = 75 *10^{-5} \ m$

the magnitude of the electric field

$E = \frac{\lambda *d}{\epsilon_o} = \frac{100*10^{-9} *75*10^{-5}}{8.854*10^{-12}} \\\\E = 8.47 \ N/C$

Therefore, the magnitude of the electric field is 8.47 N/C

6 0

3 years ago

Help in this question, please.

Mice21 [21]

C. Is the brightest ... It's connected directly across the battery. A. and B. are equal and not as bright as C ... They're in series across the battery. D. doesn't light at all ... It has a wire connected between its ends, so no voltage across it.

4 0

3 years ago

A 1700kg rhino charges at a speed of 50.0km/h. what average force is needed to bring the rhino to a stop in 0.50s?

uranmaximum [27]

From 50km/h to 0km/h in 0.5s we need next acceleration:
First we convert km/h in m/s:
50km/h = 50*1000/3600=13.8888 m/s
a = v/t = 13.88888/0.5 = 27.77777 m/s^2

Now we use Newton's law:

F=m*a

F=1700*27.7777 = 47222N

6 0

4 years ago

What is one of the fields of environmental science?

RoseWind [281]

Answer: The five major fields of environmental science are social sciences, geosciences, environmental chemistry, ecology, and atmospheric sciences.

Explanation:

3 0

2 years ago