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2 years ago

What does it mean that energy cannot be created or destroyed?

Physics

2 answers:

goldfiish [28.3K]2 years ago

8 0

Answer:

energy can only be transformed

Explanation: i took the test

dsp732 years ago

4 0

Answer:

Kinected energy cannot be transform into kinetic energy.

Explanation:

I took test

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A series circuit that is connected to a 50 V, 60 Hz source is made up of 25 ohm resistor, capacite wieh X= 18 ohms, and inductor

Allisa [31]

Answer:

the impedance of the circuit is 25.7 ohms.

Explanation:

It is given that,

Voltage, V = 50 volts

Frequency, f = 60 Hz

Resistance, R = 25 ohms

Capacitive resistance, $X_C=18\ ohms$

Inductive resistance, $X_L=24\ ohms$

We need to find the impedance of the circuit. It is given by :

$Z=\sqrt{R^2+(X_L-X_C)^2}$

$Z=\sqrt{25^2+(24-18)^2}$

Z = 25.7 ohms

So, the impedance of the circuit is 25.7 ohms. Hence, this is the required solution.

6 0

3 years ago

Two objects (42.0 and 21.0 kg) are connected by a massless string that passes over a massless, frictionless pulley. The pulley h

Kazeer [188]

Answer:

a = 3.27 m/s²

T = 275 N

Explanation:

Given that:

Mass m₁ = 42.p0 kg

Mass m₂ = 21.0 kg

Consider both masses to be in a whole system, then:

The acceleration can be determined as:

$(m_1+m_2)a = g(m_1-m_2)$

Making acceleration the subject in the above formula;

$a =\dfrac{g(m_1-m_2)}{(m_1+m_2)}$

$a =\dfrac{9.8(42.0-21.0)}{(42.0+21.0)}$

$a =\dfrac{9.8(21.0)}{(63.0)}$

$a =\dfrac{205.8}{(63.0)}$

a = 3.27 m/s²

in the string, the tension is calculated using the formula:

$T = \dfrac{2m_1m_2g}{(m_1+m_2)}$

$T = \dfrac{2(42)(21)(9.81)}{(42+21)}$

$T = \dfrac{17304.84}{63}$

T = 274.68 N

T ≅ 275 N

8 0

2 years ago

A 90 kg painter is standing on a horizontal wooden scaffolding of length 10 m, which is supported on each end by a rope. The pai

RSB [31]

Explanation:

For equilibrium, $\sum M = 0$ .

So, $8 m \times mg - (10 m) T_{1}$ = 0

$T_{1} = \frac{8 \times mg}{10}$

= $\frac{8 \times 90 \times 9.8}{10}$

= 705.6 N

Also, for equilibrium $\sum F_{y}$ = 0

$T_{1} + T_{2} - mg$ = 0

or, $T_{2} = mg - T_{1}$

= $90 \times 9.8 - 705.6$

= 176.4 N

Thus, we can conclude that the tension in the first rope is 176.4 N.

8 0

3 years ago

A 150 kg safe on frictionless casters is being raised at 1.20m to the bed of a truck using planks 4m long. The force needed to p

Vesnalui [34]

The only thing you need to know in order to solve this task is that <span>plank length (which is force x), should equal the increase in potential energy, so what we have now : (mass)* g * (height).
It has to look like that: </span>
<span>F * 3.0 = 150 x 9.81 x 1.20
Then solve for F, the result should be in newtones = 588N

Do hope it makes sense.</span>

3 0

2 years ago

The acceleration due to gravity on Jupiter is 2.5 times what it is here on earth. An object weighing 347.9 N here on earth will

inessss [21]

Answer: weight on Jupiter = 869.75 N

mass on Earth = mass on Jupiter = 35.5 Kg

Explanation:

W = mg

W = weight

m = mass

g = gravitational acceleration [ on the Earth, g₁ = 9,8 N/kg ]

On the Earth,

G₁ = m x g₁ = 347,9 N

On the Jupiter,

G₂ = mg₂

mass on the Earth = mass on the Jupiter !

m = G₁ : g = 347.9 N : 9,8 N/kg = 35.5 kg

G2 : G1 = 2.5

G₂ = 2,5 G₁ = 2,5 x 347.9 N = 869,75 N

5 0

3 years ago