1. For better aerodynamics and easier air flow while flying.
2. Because we generate friction that lights a match
4. Without friction we couldnt walk(we would slip around like on ice), cars wouldnt stick on road while driving.
3. Grooves in the tyres are designed to allow water to be expelled from beneath the tire and prevent hydroplaning.
The symbol c represents the speed of light.
Answer:
a) Her feet are in the air for 0.73+0.41 = 1.14 seconds
b) Her highest height above the board is 0.82 m
c) Her velocity when her feet hit the water is 7.16 m/s
Explanation:
t = Time taken
u = Initial velocity = 4 m/s
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²
![v=u+at\\\Rightarrow 0=4-9.81\times t\\\Rightarrow \frac{-4}{-9.81}=t\\\Rightarrow t=0.41\ s](https://tex.z-dn.net/?f=v%3Du%2Bat%5C%5C%5CRightarrow%200%3D4-9.81%5Ctimes%20t%5C%5C%5CRightarrow%20%5Cfrac%7B-4%7D%7B-9.81%7D%3Dt%5C%5C%5CRightarrow%20t%3D0.41%5C%20s)
![s=ut+\frac{1}{2}at^2\\\Rightarrow s=4\times 0.41+\frac{1}{2}\times -9.81\times 0.41^2\\\Rightarrow s=0.82\ m](https://tex.z-dn.net/?f=s%3Dut%2B%5Cfrac%7B1%7D%7B2%7Dat%5E2%5C%5C%5CRightarrow%20s%3D4%5Ctimes%200.41%2B%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20-9.81%5Ctimes%200.41%5E2%5C%5C%5CRightarrow%20s%3D0.82%5C%20m)
b) Her highest height above the board is 0.82 m
Total height she would fall is 0.82+1.8 = 2.62 m
![s=ut+\frac{1}{2}at^2\\\Rightarrow 2.62=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{2.62\times 2}{9.81}}\\\Rightarrow t=0.73\ s](https://tex.z-dn.net/?f=s%3Dut%2B%5Cfrac%7B1%7D%7B2%7Dat%5E2%5C%5C%5CRightarrow%202.62%3D0t%2B%5Cfrac%7B1%7D%7B2%7D%5Ctimes%209.81%5Ctimes%20t%5E2%5C%5C%5CRightarrow%20t%3D%5Csqrt%7B%5Cfrac%7B2.62%5Ctimes%202%7D%7B9.81%7D%7D%5C%5C%5CRightarrow%20t%3D0.73%5C%20s)
a) Her feet are in the air for 0.73+0.41 = 1.14 seconds
![v=u+at\\\Rightarrow v=0+9.81\times 0.73\\\Rightarrow v=7.16\ m/s](https://tex.z-dn.net/?f=v%3Du%2Bat%5C%5C%5CRightarrow%20v%3D0%2B9.81%5Ctimes%200.73%5C%5C%5CRightarrow%20v%3D7.16%5C%20m%2Fs)
c) Her velocity when her feet hit the water is 7.16 m/s
<span>Answer:
P(V2-V1)
10(.5-.01)
10(.49)
=4.9 L x ATM (101.3)= 496.37 J</span>
Answer:
b. Pascal
Explanation:
Pressure is defined as the ratio between a force and the surface area on which the force is applied:
![p=\frac{F}{A}](https://tex.z-dn.net/?f=p%3D%5Cfrac%7BF%7D%7BA%7D)
where F is the force and A is the area.
The force is measured in Newtons (N), while the area is measured in squared meters (
), so the Pascal (Pa), which is the units of measure of the pressure, is defined as:
![[Pa]=\frac{[N]}{[m^2]}](https://tex.z-dn.net/?f=%5BPa%5D%3D%5Cfrac%7B%5BN%5D%7D%7B%5Bm%5E2%5D%7D)