Answer:
They contain iron.
Explanation:
Iron is made of metal and magnets attract to metal Iron.
The heat Q transferred to cause a temperature change depends on the magnitude of the temperature change, the mass of the system, and the substance and phase involved.
Explanation:
https://courses.lumenlearning.com/physics/chapter/14-2-temperature-change-and-heat-capacity/
Answer:
A) a = 2.31[m/s^2]; B) t = 14.4 [s]
Explanation:
We can solve this problem using the kinematic equations, but firts we must identify the data:
Vf= final velocity = take off velocity = 120[km/h]
Vi= initial velocity = 0, because the plane starts to move from the rest.
dx= distance to run = 240 [m]
![v_{f} ^{2} =v_{i} ^{2}+2*g*dx\\where:\\v_{f}=120[\frac{km}{h} ]*\frac{1hr}{3600sg} * \frac{1000m}{1km} =33.33[m/s]\\\\Replacing\\33.33^{2}=0+2*a*(240)\\ a=\frac{11108.88}{2*240}\\ a=2.31[m/s^2]\\](https://tex.z-dn.net/?f=v_%7Bf%7D%20%5E%7B2%7D%20%3Dv_%7Bi%7D%20%5E%7B2%7D%2B2%2Ag%2Adx%5C%5Cwhere%3A%5C%5Cv_%7Bf%7D%3D120%5B%5Cfrac%7Bkm%7D%7Bh%7D%20%5D%2A%5Cfrac%7B1hr%7D%7B3600sg%7D%20%2A%20%5Cfrac%7B1000m%7D%7B1km%7D%20%3D33.33%5Bm%2Fs%5D%5C%5C%5C%5CReplacing%5C%5C33.33%5E%7B2%7D%3D0%2B2%2Aa%2A%28240%29%5C%5C%20a%3D%5Cfrac%7B11108.88%7D%7B2%2A240%7D%5C%5C%20%20a%3D2.31%5Bm%2Fs%5E2%5D%5C%5C)
To find the time we must use another kinematic equation.
![v_{f} =v_{i} +a*t\\replacing:\\33.33=0+(2.31*t)\\t=\frac{33.33}{2.31}\\ t=14.4[s]](https://tex.z-dn.net/?f=v_%7Bf%7D%20%3Dv_%7Bi%7D%20%2Ba%2At%5C%5Creplacing%3A%5C%5C33.33%3D0%2B%282.31%2At%29%5C%5Ct%3D%5Cfrac%7B33.33%7D%7B2.31%7D%5C%5C%20t%3D14.4%5Bs%5D)
Average speed is the ratio of total distance moved by Chi in total time interval
So here we will have
Total distance = 100 m + 400 m
![d = 500 m = 0.5 km](https://tex.z-dn.net/?f=d%20%3D%20500%20m%20%3D%200.5%20km)
Total time taken = 5 min + 15 min = 20 min
![T = \frac{20}{60} = \frac{1}{3} hour](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B20%7D%7B60%7D%20%3D%20%5Cfrac%7B1%7D%7B3%7D%20hour)
now by the formula of average speed we know that
![v_{avg} = \frac{d}{T}](https://tex.z-dn.net/?f=v_%7Bavg%7D%20%3D%20%5Cfrac%7Bd%7D%7BT%7D)
![v_{avg} = \frac{0.5 km}{1/3 h}](https://tex.z-dn.net/?f=v_%7Bavg%7D%20%3D%20%5Cfrac%7B0.5%20km%7D%7B1%2F3%20h%7D)
![v_{avg} = 1.5 km/h](https://tex.z-dn.net/?f=v_%7Bavg%7D%20%3D%201.5%20km%2Fh)
so average speed will be 1.5 km/h