All categories

3 years ago

35 POINTSS!!! PLSSSS HELLPPP!!!

Physics

1 answer:

Crazy boy [7]3 years ago

6 0

Answer:

beacuse:

Energy can be transferred from one object to another by doing work. ... When work is done, energy is transferred from the agent to the object, which results in a change in the object's motion (more specifically, a change in the object's kinetic energy).

You might be interested in

PLEASE HELP ME 45 POINTS

sergij07 [2.7K]

Answer:

a) We kindly invite you to see the explanation and the image attached below.

b) The acceleration of the masses is 4.203 meters per square second.

c) The tension force in the cord is 28.02 newtons.

d) The system will take approximately 0.845 seconds to cover a distance of 1.5 meters.

e) The final speed of the system is 3.551 meters per second.

Explanation:

a) At first we assume that pulley and cord are both ideal, that is, masses are negligible and include the free body diagrams of each mass and the pulley in the image attached below.

b) Both masses are connected to each other by the same cord, the direction of acceleration will be dominated by the mass of greater mass (mass A) and both masses have the same magnitude of acceleration. By the 2nd Newton's Law, we create the following equation of equilibrium:

Mass A

$\Sigma F = T - m_{A}\cdot g = -m_{A}\cdot a$ (1)

Mass B

$\Sigma F = T - m_{B}\cdot g = m_{B}\cdot a$ (2)

Where:

$T$ - Tension force in the cord, measured in newtons.

$m_{A}$ , $m_{B}$ - Masses of blocks A and B, measured in kilograms.

$g$ - Gravitational acceleration, measured in meters per square second.

$a$ - Net acceleration of the each block, measured in meters per square second.

By subtracting (2) by (1), we get an expression for the acceleration of each mass:

$m_{B}\cdot a +m_{A}\cdot a = T-m_{B}\cdot g -T + m_{A}\cdot g$

$(m_{B}+m_{A})\cdot a = (m_{A}-m_{B})\cdot g$

$a = \frac{m_{A}-m_{B}}{m_{B}+m_{A}} \cdot g$

If we know that $m_{A} = 5\,kg$ , $m_{B} = 2\,kg$ and $g = 9.807\,\frac{m}{s^{2}}$ , then the acceleration of the masses is:

$a = \left(\frac{5\,kg-2\,kg}{5\,kg+2\,kg}\right) \cdot\left(9.807\,\frac{m}{s^{2}} \right)$

$a = 4.203\,\frac{m}{s^{2}}$

The acceleration of the masses is 4.203 meters per square second.

c) From (2) we get the following expression for the tension force in the cord:

$T = m_{B}\cdot (a+g)$

If we know that $m_{B} = 2\,kg$ , $g = 9.807\,\frac{m}{s^{2}}$ and $a = 4.203\,\frac{m}{s^{2}}$ , then the tension force in the cord:

$T = (2\,kg)\cdot \left(4.203\,\frac{m}{s^{2}}+9.807\,\frac{m}{s^{2}} \right)$

$T = 28.02\,N$

The tension force in the cord is 28.02 newtons.

d) Given that system starts from rest and net acceleration is constant, we determine the time taken by the block to cover a distance of 1.5 meters through the following kinematic formula:

$\Delta y = \frac{1}{2}\cdot a\cdot t^{2}$ (3)

Where:

$a$ - Net acceleration, measured in meters per square second.

$t$ - Time, measured in seconds.

$\Delta y$ - Covered distance, measured in meters.

If we know that $a = 4.203\,\frac{m}{s^{2}}$ and $\Delta y = 1.5\,m$ , then the time taken by the system is:

$t = \sqrt{\frac{2\cdot \Delta y}{a} }$

$t = \sqrt{\frac{2\cdot (1.5\,m)}{4.203\,\frac{m}{s^{2}} } }$

$t \approx 0.845\,s$

The system will take approximately 0.845 seconds to cover a distance of 1.5 meters.

e) The final speed of the system is calculated by the following formula:

$v = a\cdot t$ (4)

Where $v$ is the final speed of the system, measured in meters per second.

If we know that $a = 4.203\,\frac{m}{s^{2}}$ and $t \approx 0.845\,s$ , then the final speed of the system is:

$v = \left(4.203\,\frac{m}{s^{2}} \right)\cdot (0.845\,s)$

$v = 3.551\,\frac{m}{s}$

The final speed of the system is 3.551 meters per second.

8 0

3 years ago

If the student hit a drum in his bedroom how would the sound wave behave differently than if he hit it in a swimming pool? Pleas

zlopas [31]

The sound wave would behave differently in a swimming pool than in his bedroom because sound waves travel faster in more dense mediums; such as water. The wave will travel faster in water, and slower in air.

4 0

3 years ago

A boat moves 60 kilometers east from point A to point B. There, it reverses direction and travels another 45 kilometers toward p

Alexxx [7]

Answer:1) the total distance is the sum of the two distances

60 km + 45 km = 105 km

2) The displacement is the net movement, or the difference between the initial position and the final position

Call x the initial position, then the final position is x + [60km - 45km]

And the displacement is x + (60km - 45km) - x =60km -45 km = 15 km

Explanation:

6 0

3 years ago

How many milligrams are equal to 8 grams?

Andre45 [30]

Answer:

it should be 8,000

Explanation:

because if you multiply the mass value by 1000, you will get 8,000

:):):):)

6 0

3 years ago

Liquid water can be separated into hydrogen gas and oxygen gas through electrolysis. 1 mole of hydrogen gas and 0.5 moles of

den301095 [7]

The temperature of the oxygen gas is 243.75 K.

Using ideal gas law to explain the answer, the absolute temperature of the gas will decrease if the number of moles of the gas increases and it will increase if the volume and/or pressure of the gas increases.

The reaction of the given elements;

$H_2 \ + \ \frac{1}{2} O_2 \ --->\ \ H_2O$

volume of the collected oxygen gas, V = 10 L

pressure of the gas, P = 1 atm

number of moles of the gas, n = 0.5

Using ideal law the temperature of the oxygen gas is calculated as follows;

$PV = nRT\\\\T = \frac{PV}{nR} \\\\where;\\R \ is \ the \ ideal \ gas \ constant = 0.08205 \ L.atm/K.mol\\\\T = \frac{1 \times 10 }{0.5 \times 0.08205} \\\\T = 243.75 \ K$

Thus, the temperature of the gas is 243.75 K.

Using ideal gas law to explain the answer. The absolute temperature of the oxygen gas is directly proportional to the product of its pressure and volume and inversely proportional to its number of moles. That is the absolute temperature of the gas will decrease if the number of moles of the gas increases and it will increase if the volume and/or pressure increases.

Learn more here: brainly.com/question/16617695

8 0

3 years ago