Hundreds of millions of years ago, all the continents on Earth were connected to form a giant “supercontinent” called Pangaea. H
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Answer:
1.28 m
Explanation:
As shown in the diagram attached,
According to the principle of moment,
For a body at equilibrium,
Sum of clockwise moment = sum of anticlockwise moment.
Taking moment about the pivot,
W₁(1.6)+W(0.133) = W₂(x)............... Equation 1
Where W₁ = Weight of the first child, Wₓ = Weight of the seesaw, W₂ = weight of the second child, x = distance of the second child from the pivot.
But,
W = mg
Where g = 9.8 m/s², m = mass of the body
Therefore,
W₁ = 26×9.8 = 254.8 N,
Wₓ = 18×9.8 = 176.4 N
W₂ = 34.4×9.8 = 337.12 N
Substitute these values into equation 1
(254.8×1.6)+(176.4×0.133) = 337.12(x)
407.68+23.4612 = 337.12x
337.12x = 431.1412
x = 431.1412/337.12
x = 1.2789
x ≈ 1.28 m
Answer:
The efficiency of the system is 63.7 %
Explanation:
Given;
input power of the motor, = 1.5 kW = 1,500 W
mass of the car lifted, m = 1300 kg
height through which the car was lifted, h = 1.8 m
time, t = 24 s
The output power of the motor is calculated as;
Output Power = F x v
= (mg) x (d/t)
= (1300 x 9.8) x (1.8 / 24)
= 12,740 x 0.075
= 955.5 W
The efficiency of the system is calculated as;
The correct answer is 63.7%