The answer is C -
because reversibility means when taking a break it'll be hard to get back on schedule
Answer:
B
Explanation:
a force acting upon an object increases that objects acceleration
Recall that
![{v_f}^2-{v_i}^2=2a\Delta x](https://tex.z-dn.net/?f=%7Bv_f%7D%5E2-%7Bv_i%7D%5E2%3D2a%5CDelta%20x)
where
and
are the initial and final velocities, respecitvely;
is the acceleration; and
is the change in position.
So we have
![\left(21\dfrac{\rm m}{\rm s}\right)^2-{v_i}^2=2\left(0.853\dfrac{\rm m}{\mathrm s^2}\right)(120\,\mathrm m)](https://tex.z-dn.net/?f=%5Cleft%2821%5Cdfrac%7B%5Crm%20m%7D%7B%5Crm%20s%7D%5Cright%29%5E2-%7Bv_i%7D%5E2%3D2%5Cleft%280.853%5Cdfrac%7B%5Crm%20m%7D%7B%5Cmathrm%20s%5E2%7D%5Cright%29%28120%5C%2C%5Cmathrm%20m%29)
![\implies v_i\approx\boxed{15.4\dfrac{\rm m}{\rm s}}](https://tex.z-dn.net/?f=%5Cimplies%20v_i%5Capprox%5Cboxed%7B15.4%5Cdfrac%7B%5Crm%20m%7D%7B%5Crm%20s%7D%7D)
(Normally, this equation has two solutions, but we omit the negative one because the car is moving in one direction.)
Answer:
The value is ![A = 2.80 *10^{-4} \ m^2](https://tex.z-dn.net/?f=A%20%3D%20%202.80%20%2A10%5E%7B-4%7D%20%5C%20%20m%5E2)
Explanation:
From the question we are told that
The operating temperature is ![T = 2450 \ K](https://tex.z-dn.net/?f=T%20%20%3D%20%202450%20%5C%20%20K)
The emissivity is ![e = 0.350](https://tex.z-dn.net/?f=e%20%3D%20%200.350)
The power rating is ![P = 200 \ W](https://tex.z-dn.net/?f=P%20%20%3D%20%20200%20%5C%20%20W)
Generally the area is mathematically represented as
![A = \frac{P}{ e * \sigma * T^2}](https://tex.z-dn.net/?f=A%20%3D%20%5Cfrac%7BP%7D%7B%20e%20%2A%20%20%5Csigma%20%20%2A%20%20T%5E2%7D)
Where
is the Stefan Boltzmann constant with value
![\sigma = 5.67 *10^{-8} \ W/m^2\cdot K^4](https://tex.z-dn.net/?f=%5Csigma%20%20%3D%20%205.67%20%2A10%5E%7B-8%7D%20%5C%20%20W%2Fm%5E2%5Ccdot%20K%5E4)
So
![A = \frac{200}{0.350 * 5.67*10^{-8} * 2450^{4}}](https://tex.z-dn.net/?f=A%20%3D%20%20%5Cfrac%7B200%7D%7B0.350%20%2A%20%205.67%2A10%5E%7B-8%7D%20%2A%20%202450%5E%7B4%7D%7D)
![A = 2.80 *10^{-4} \ m^2](https://tex.z-dn.net/?f=A%20%3D%20%202.80%20%2A10%5E%7B-4%7D%20%5C%20%20m%5E2)