I would think force. Because friction has to have force to work ^-^
Rust, photosynthesis, and heat from fire are all chemical reactions <span>because </span>new substances are formed and the chemical formula is changed. By doing this, bonds are broken and formed in the making of the new substance. Melting ice is physical change the molecules are still water molecules, it just changed physical form.
The period of a simple pendulum is given by:
![T=2 \pi \sqrt{ \frac{L}{g} }](https://tex.z-dn.net/?f=T%3D2%20%5Cpi%20%20%5Csqrt%7B%20%5Cfrac%7BL%7D%7Bg%7D%20%7D%20)
where L is the pendulum length, and g is the gravitational acceleration of the planet. Re-arranging the formula, we get:
![g= \frac{4 \pi^2}{T^2}L](https://tex.z-dn.net/?f=g%3D%20%5Cfrac%7B4%20%5Cpi%5E2%7D%7BT%5E2%7DL%20)
(1)
We already know the length of the pendulum, L=1.38 m, however we need to find its period of oscillation.
We know it makes N=441 oscillations in t=1090 s, therefore its frequency is
![f= \frac{N}{t}= \frac{441}{1090 s}=0.40 Hz](https://tex.z-dn.net/?f=f%3D%20%5Cfrac%7BN%7D%7Bt%7D%3D%20%5Cfrac%7B441%7D%7B1090%20s%7D%3D0.40%20Hz%20%20)
And its period is the reciprocal of its frequency:
![T= \frac{1}{f}= \frac{1}{0.40 Hz}=2.47 s](https://tex.z-dn.net/?f=T%3D%20%5Cfrac%7B1%7D%7Bf%7D%3D%20%5Cfrac%7B1%7D%7B0.40%20Hz%7D%3D2.47%20s%20%20)
So now we can use eq.(1) to find the gravitational acceleration of the planet:
Answer:
The answer to your question is:
a) t = 3.81 s
b) vf = 37.4 m/s
Explanation:
Data
height = 71.3 m = 234 feet
t = 0 m/s
vf = ?
vo = 0 m/s
Formula
h = vot + 1/2gt²
vf = vo + gt
Process
a)
h = vot + 1/2gt²
71.3 = 0t + 1/2(9.81)t²
2(71.3) = 9,81t²
t² = 2(71.3)/9.81
t² = 14.53
t = 3.81 s
b)
vf = 0 + (9.81)(3.81)
vf = 37.4 m/s
Answer:![32.77\ mi/hr](https://tex.z-dn.net/?f=32.77%5C%20mi%2Fhr)
Explanation:
Given
Initially Reading on the odometer is ![31,500\ miles](https://tex.z-dn.net/?f=31%2C500%5C%20miles)
Final reading on the odometer is ![31,713\ miles](https://tex.z-dn.net/?f=31%2C713%5C%20miles)
Time taken is ![t=6.5\ hr](https://tex.z-dn.net/?f=t%3D6.5%5C%20hr)
average velocity ![=\dfrac{\text{Displacement}}{\text{time}}](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B%5Ctext%7BDisplacement%7D%7D%7B%5Ctext%7Btime%7D%7D)
![v_{avg}=\dfrac{31713-31500}{6.5}](https://tex.z-dn.net/?f=v_%7Bavg%7D%3D%5Cdfrac%7B31713-31500%7D%7B6.5%7D)
![v_{avg}=\dfrac{213}{6.5}](https://tex.z-dn.net/?f=v_%7Bavg%7D%3D%5Cdfrac%7B213%7D%7B6.5%7D)
![v_{avg}=32.77\ mi/hr](https://tex.z-dn.net/?f=v_%7Bavg%7D%3D32.77%5C%20mi%2Fhr)
Thus the average velocity of mail truck is ![32.77\ mi/hr](https://tex.z-dn.net/?f=32.77%5C%20mi%2Fhr)