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2 years ago

What are similarities and differences of the 1st, 2nd, and 3rd class levers?

1 answer:

7 0

Similarities:
-- All three classes have a fulcrum (pivot).
-- All three classes have a point where the effort force is applied.
-- All three classes have a point where the load or resistance force is applied.
-- If you can find a place to stand and a lever that's long enough,
then you can move the Earth with a 1st or 2nd Class lever.

Differences:
-- The mechanical advantage of a 1st Class lever
can be greater than 1, equal to 1, or less than 1.
-- The mechanical advantage of a 2nd Class lever is always more than 1 .
-- The mechanical advantage of a 3rd Class lever is always less than 1 .

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I will mark you as brainliest if you answer correctly

aleksklad [387]

(A) We can solve the problem by using Ohm's law, which states:
$V=IR$
where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know $V=220 V$ and $R=220 \Omega$ , therefore we can rearrange Ohm's law to find the current through the device:
$I= \frac{V}{R}= \frac{220 V}{220 \Omega}=1 A$

(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:
$R= \rho \frac{L}{A}$
where
$\rho$ is the resistivity of the material of the wire
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.

6 0

2 years ago

Hii can someone please doo this! 50 pointss.

andrey2020 [161]

Answer:

The periodic table illustrate some of the elements from Hydrogen to Calcium

8 0

2 years ago

Please help me solve all of them ( a, b, c and d ) thankiew !! <br> I’m also kind of in a rush

Sergio039 [100]

Answer:

V= IR

9V = I ×( 12+6)

I = 9/ 18 A = 0.5 A

V=IR

240 = 6 A ×( 20 + R)

40 = 20 + R

R = 20 ohm

resultant resistance of the 2 parallel resistances= Ro

1/Ro = 1/ 5 + 1/ 20

1/Ro =( 20+5)/100

= 1/Ro = 1/4

Ro= 4 ohm

V=IR

V = 2A × ( 1+ 4 OHM)

V = 10V

equivalent resistance = Ro

1/Ro = 1/(2+8) + 1/(5+5)

1/Ro = 1/10 +1/10

2/10 = 1/ Ro

Ro= 10/2 = 5 ohm

V = IR

12V = I × 5Ohm

I=2.4 A

6 0

1 year ago

Explain why a moving object cannot come to a stop instantaneously (in zero seconds). Hint: Think about the acceleration that wou

gizmo_the_mogwai [7]

To stop instantly, you would need infinite deceleration. This in turn, requires infinite force, as demonstrable with this equation:F=ma<span>So when you hit a wall, you do not instantly stop (e.g. the trunk of the car will still move because the car is getting crushed). In a case of a change in momentum, </span><span><span>m<span>v⃗ </span></span><span>m<span>v→</span></span></span>, we can use the following equation to calculate force:F=p/h<span>However, because the force is nowhere close to infinity, time will never tend to zero either, which means that you cannot come to an instantaneous stop.</span>

7 0

2 years ago

A sports car accelerates from rest for 5 seconds reaching a velocity of 23.0 m/s.

denis-greek [22]

Answer:

Explanation:

The acceleration of an object given it's velocity and time taken can be found by using the formula

where

v is the final velocity

u is the initial velocity

t is the time taken

a is the acceleration

Since the body is from rest u = 0

From the question we have

$a = \frac{23 - 0}{5} = \frac{23}{5} \\$

We have the final answer as

Hope this helps you

4 0

1 year ago