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3 years ago

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A new spacecraft is built with an engine that is able to produce constant acceleration of 1g, where g = gravity’s acceleration o

n earth = 10m/s^2. A) calculate how long it would take the starship to reach a velocity of 0.9c where c is the speed of light. B) calculate how far the spaceship would travel during this time and compare this to our nearest neighbor in space, Alpha Centauri

1 answer:

QveST [7]3 years ago

3 0

given that acceleration due to gravity is g = 10 m/s^2

speed of the rocket will reach to 0.9c

$v_f = 0.9* 3 * 10^8 = 2.7 * 10^8 m/s$

now by kinematics

$v_f = v_i + a*t$

$2.7 * 10^8 = 0 + 10*t$

$t = 2.7*10^7 s$

Part b)

distance traveled by it in above time

$d = v*t + \frac{1}{2}at^2$

$d = 0 + \frac{1}{2}*10*(2.7*10^7)^2$

$d = 3.645 * 10^{15} m$

so this is the distance covered by the object

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Answer:

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The linear co-efficient of thermal expansion of copper ( ∝ ) = 1.6 × 10⁻⁶ /°C

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$\begin{aligned}\sum H& =0\\-R_A+R_C&=0\\R_A&=R_C\\R_A&=R\\R_C&=R\\R_{A}&=\text{reaction\:force\:at\:A}\\R_{C}&=\text{reaction\:force\:at\:C}\\\sigma_{AB}&=\text{axial\:stress\:at\:A}\\\sigma_{BC}&=\text{axial\:stress\:at\:B}\\\sigma_{AB}&=\frac{R}{A_{A}}\\&=\frac{R_{A}}{A_{A}}\\\sigma_{BC}&=\frac{R_{B}}{A_{B}}\\&=\frac{R}{A_{B}}\\\frac{\sigma_{AB}}{\sigma_{BC}}&=\frac{A_{B}}{A_{B}}\\&=\frac{\frac{\pi}{4}\cdot 150^{2}}{\frac{\pi}{4}\cdot 200^{2}}\\&=\frac{9}{16}\end{aligned}$

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