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4 years ago

10 POINT PLS HELP

1 answer:

5 0

Answer: A heat engine cannot be 100% efficient because, according to the law, energy added as heat is always greater than energy removed as heat.

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If the 15.0 cm string is shorter than the 30.0 cm string.

Margaret [11]

Answer:

option c) 2 is the right answer

7 0

3 years ago

A spaceship, at rest in some inertial frame in space, suddenly needs to accelerate. The ship forcibly expels 103 kg of fuel from

Cerrena [4.2K]

Answer:

$V_s = 1.8*10^5m/s$

Explanation:

There is no external force applied, therefore there is a moment's preservation throughout the trajectory.

Initial momentum = Final momentum.

The total mass is equal to

$m_T= m_1 +m_2$

Where,

$m_1 =$ mass of ship

$m_2 =$ mass of fuell expeled.

As the moment is conserved we have,

$0=V_fm_2+V_sm_1$

Where,

$V_f =$ Velocity of fuel

$V_s =$ Velocity of Space Ship

Solving and re-arrange to $V_s$ we have,

$V_s = \frac{V_f m_2 }{m_1}$

$V_s = \frac{3/5c}{10^6}$

$V_s = 3.5*10^{-3}c$

Where c is the speed of light.

Therefore the ship be moving with speed

$V_s = \frac{3}{5}*10^{-3}*3*10^8m/s$

$V_s = 1.8*10^5m/s$

5 0

3 years ago

A rightward force of 246 N is applied to a 35 N suitcase to accelerate it across the floor. The coefficient of friction between

katrin [286]

(35/g) = mass of 3.57kg. (9.8 for g).
 (35 x 0.75) = 26.25N. friction.
 (246 - 26.25) = net 219.76N. accelerating force.
 Aceleration = (f/m) = (219.76/3.57) = 61.56m/sec^2

5 0

3 years ago

A rotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be cr

Grace [21]

Answer: 0.313 rad/s

Explanation:

The equation that relates the velocity $V$ and the angular velocity $\omega$ in the uniform circular motion is:

$V=\omega.r$ (1)

Where $r=d/2=100m$ is the radius of the space station (with a diaeter of 200m) that describes the uniform circular motion.

Isolating $\omega$ from (1):

$\omega=\frac{V}{r}$ (2)

On the other hand, we are told the “artificial gravity” produced by the cetripetal acceleration $a_{c}$ is $9.8m/s^{2}$ , and is given by the following equation: