Answer:
8 to 10 times
Explanation:
For dry road
u= 15 mph ( 1 mph = 0.44 m/s)
u= 6.7 m/s
Let take coefficient of friction( μ) of dry road is 0.7
So the de acceleration a = μ g
a= 0.7 x 10 m/s ² ( g=10 m/s ²)
a= 7 m/s ²
We know that
v= u - a t
Final speed ,v=0
0 = 6.7 - 7 x t
t= 0.95 s
For snow road
μ = 0.4
de acceleration a = μ g
a = 0.4 x 10 = 4 m/s ²
u= 30 mph= 13.41 m/s
v= u - a t
Final speed ,v=0
0 = 30 - 4 x t'
t'=7.5 s
t'=7.8 t
We can say that it will take 8 to 10 times more time as compare to dry road for stopping the vehicle.
8 to 10 times
Answer:
1) 
2) 
Explanation:
For isothermal process n =1
![V_o = \frac{5}{[\frac{72}{80}]^{1/1} -[\frac{72}{180}]^{1/1}}](https://tex.z-dn.net/?f=V_o%20%20%3D%20%5Cfrac%7B5%7D%7B%5B%5Cfrac%7B72%7D%7B80%7D%5D%5E%7B1%2F1%7D%20-%5B%5Cfrac%7B72%7D%7B180%7D%5D%5E%7B1%2F1%7D%7D)
calculate pressure ratio to determine correction factor
correction factor for calculate dpressure ration for isothermal process is
c1 = 1.03
b) for adiabatic process
n =1.4
volume of hydraulic accumulator is given as
![V_o =\frac{\Delta V}{[\frac{p_o}{p_1}]^{1/n} -[\frac{p_o}{p_2}]^{1/n}}](https://tex.z-dn.net/?f=V_o%20%3D%5Cfrac%7B%5CDelta%20V%7D%7B%5B%5Cfrac%7Bp_o%7D%7Bp_1%7D%5D%5E%7B1%2Fn%7D%20-%5B%5Cfrac%7Bp_o%7D%7Bp_2%7D%5D%5E%7B1%2Fn%7D%7D)
![V_o = \frac{5}{[\frac{72}{80}]^{1/1.4} -[\frac{72}{180}]^{1/1.4}}](https://tex.z-dn.net/?f=V_o%20%20%3D%20%5Cfrac%7B5%7D%7B%5B%5Cfrac%7B72%7D%7B80%7D%5D%5E%7B1%2F1.4%7D%20-%5B%5Cfrac%7B72%7D%7B180%7D%5D%5E%7B1%2F1.4%7D%7D)
calculate pressure ratio to determine correction factor
correction factor for calculate dpressure ration for isothermal process is
c1 = 1.15
Answer:
a)We know that acceleration a=dv/dt
So dv/dt=kt^2
dv=kt^2dt
Integrating we get
v(t)=kt^3/3+C
Puttin t=0
-8=C
Putting t=2
8=8k/3-8
k=48/8
k=6
Answer:
Explanation:
Let assume that heating and boiling process occurs under an athmospheric pressure of 101.325 kPa. The heat needed to boil water is:
![Q_{water} = (1.4\,L)\cdot(\frac{1\,m^{3}}{1000\,L} )\cdot (1000\,\frac{kg}{m^{3}} )\cdot [(4.187\,\frac{kJ}{kg\cdot ^{\textdegree}C} )\cdot (100^{\textdegree}C-25^{\textdegree}C)+2257\,\frac{kJ}{kg}]](https://tex.z-dn.net/?f=Q_%7Bwater%7D%20%3D%20%281.4%5C%2CL%29%5Ccdot%28%5Cfrac%7B1%5C%2Cm%5E%7B3%7D%7D%7B1000%5C%2CL%7D%20%29%5Ccdot%20%281000%5C%2C%5Cfrac%7Bkg%7D%7Bm%5E%7B3%7D%7D%20%29%5Ccdot%20%5B%284.187%5C%2C%5Cfrac%7BkJ%7D%7Bkg%5Ccdot%20%5E%7B%5Ctextdegree%7DC%7D%20%29%5Ccdot%20%28100%5E%7B%5Ctextdegree%7DC-25%5E%7B%5Ctextdegree%7DC%29%2B2257%5C%2C%5Cfrac%7BkJ%7D%7Bkg%7D%5D)
The heat liberated by the LP gas is:
A kilogram of LP gas has a minimum combustion power of 
. Then, the required mass is:
Answer:
The final velocity of the rocket is 450 m/s.
Explanation:
Given;
initial velocity of the rocket, u = 0
constant upward acceleration of the rocket, a = 18 m/s²
time of motion of the rocket, t = 25 s
The final velocity of the rocket is calculated with the following kinematic equation;
v = u + at
where;
v is the final velocity of the rocket after 25 s
Substitute the given values in the equation above;
v = 0 + 18 x 25
v = 450 m/s
Therefore, the final velocity of the rocket is 450 m/s.
