Answer:
(a) 
(b) 
Explanation:
Part (a)
The total length of copper cord L=86.3 m
The cross sectional area A=1.71×10⁻⁶m²
The resistivity of copper p=1.72×10⁻⁸Ω
Thus the resistance of extension cord is
Part (b)
The resistance of trimmer Rt=17.9 ohms
When voltage of 120V is applied then the current I is passing through series circuit is
Thus the voltage across the trimmer is:
Answer:
Maximum speed of the car is 17.37 m/s.
Explanation:
Given that,
Radius of the circular track, r = 79 m
The coefficient of friction, 
To find,
The maximum speed of car.
Solution,
Let v is the maximum speed of the car at which it can safely travel. It can be calculated by balancing the centripetal force and the gravitational force acting on it as :
v = 17.37 m/s
So, the maximum speed of the car is 17.37 m/s.
Scientists have been observing Earth for a long time. They use NASA satellites and other instruments to collect many types of information about Earth's land, atmosphere, ocean and ice. This information tells us that Earth's climate is getting warmer.
Extra:
Extra greenhouse gases in our atmosphere are the main reason that Earth is getting warmer. Greenhouse gases, such as carbon dioxide (CO2) and methane, trap the Sun's heat in Earth's atmosphere.
It's normal for there to be some greenhouse gases in our atmosphere. They help keep Earth warm enough to live on. But too many greenhouse gases can cause too much warming.
The burning of fossil fuels like coal and oil increase the amount of CO2 in our air. This happens because the burning process combines carbon with oxygen in the air to make CO2.
It's important that we monitor CO2 levels, because too much CO2 can cause too much warming on Earth. Several NASA missions have instruments that study CO2 in the atmosphere.
Answer:
Explanation:
The resistors in a unbalanced wheat stone bridge cannot be treated as a combination of series and parallel combination of resistors.
In case of balanced wheat stone bridge, the resistors can be treated as the combination of series and parallel combination.
Here, In the balanced wheat stone bridge
R1 and R2 be in series and Ra and Rx is series and then their combination is in parallel combination.
Answer:
776.6 w
1.04 hp
Explanation:
given:
Mass, m = 190kg
height change, h = 25m
time elapsed, t = 60 s
acceleration due to gravity, g = 9.81 m/s²
Potential energy required raising 190 kg of water to a height of 25m
= mgh
= 190 x 9.81 x 25
= 46,597.5 J
Power required in 60 s
= Energy required ÷ time elapsed
= 46,597.5 ÷ 60
= 776.6 Watts (Use conversion 1 W = 0.00134102 hp)
= 776.6 w x 0.00134102 hp/w
= 1.04 hp
