Answer:
36.87 km/h
Explanation:
Convert all the units in SI system
1 mile = 1609.34 m
d1 = 6 mi = 9656.04 m
t1 = 15 min = 15 x 60 = 900 s
d2 = 3 mi = 4828.02 m
t2 = 10 min = 10 x 60 = 600 s
d3 = 1 mi = 1609.34 m
t3 = 2 min = 2 x 60 = 120 s
d4 = 0.5 mi = 804.67 m
t4 = 0.5 min = 0.5 x 60 = 30 s
Total distance, d = d1 + d2 + d3 + d4
d = 9656.04 + 4828.02 + 1609.34 + 804.67 = 16898.07 m = 16.898 km
total time, t = t1 + t2 + t3 + t4
t = 900 + 600 + 120 + 30 = 1650 s = 0.4583 h
The ratio of the total distance covered to the total time taken is called average speed.
Average speed = 16.898 / 0.4583 = 36.87 km/h
Hello!
A portable DVD player requires six 1.5-volt batteries to operate. If the resistance in the circuit is 7.2 ohms, what is the current?
Data:
We have six 1.5 volt batteries, soon, your tension (V)
V = 1.5 * 6 = 9 Volts
R (resistance) = 7.2 ohms
I (Current intensity) = ? (in Amps)
Solving (Ohm's First Law):
![I = \dfrac{V}{R}](https://tex.z-dn.net/?f=I%20%3D%20%5Cdfrac%7BV%7D%7BR%7D)
![I = \dfrac{9}{7.2}](https://tex.z-dn.net/?f=I%20%3D%20%5Cdfrac%7B9%7D%7B7.2%7D)
![\boxed{\boxed{I= 1.25\:A}}\end{array}}\qquad\checkmark](https://tex.z-dn.net/?f=%5Cboxed%7B%5Cboxed%7BI%3D%201.25%5C%3AA%7D%7D%5Cend%7Barray%7D%7D%5Cqquad%5Ccheckmark)
Answer:
The current is 1.25 amps
_______________________
I Hope this helps, greetings ... Dexteright02! =)
Total resistance = voltage / current = 220 / 5 = 44 ohms .
Even one 176-ohm resistor is too much. The current through it is 1.25 A,
and more than one of them in series reduces the current even further.
Connecting them in <em><u>parallel</u></em>, however . . .
Four resistors of 176-ohms each, in <u>parallel</u>, have a net effective resistance
of 176/4 = 44 ohms ... exactly what you need to do the job.
A person runs up 40 stairs and then come down 10 steps
So total stairs upwards is given as
![N = 40 - 10 = 30](https://tex.z-dn.net/?f=N%20%3D%2040%20-%2010%20%3D%2030)
now here we will have total height reached
![H = N\times h](https://tex.z-dn.net/?f=H%20%3D%20N%5Ctimes%20h)
![H = 30 \times 0.25 = 7.5 m](https://tex.z-dn.net/?f=H%20%3D%2030%20%5Ctimes%200.25%20%3D%207.5%20m)
Now total energy used or mechanical work done is
![W = mgH](https://tex.z-dn.net/?f=W%20%3D%20mgH)
![W = 790 \times 7.5 = 5925 J](https://tex.z-dn.net/?f=W%20%3D%20790%20%5Ctimes%207.5%20%3D%205925%20J)
Now the mechanical power is given as
![P = \frac{W}{t}](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BW%7D%7Bt%7D)
![P = \frac{5925}{20+ 5} = 237 W](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7B5925%7D%7B20%2B%205%7D%20%3D%20237%20W)