750W 30mins...750x30x60 joules ... 75000x18 ... about 1,500,000j
D
Answer:
Explanation:
Before it hits the ground:
The initial potential energy = the final potential energy + the kinetic energy
mgH = mgh + 1/2 mv²
gH = gh + 1/2 v²
v = √(2g (H - h))
v = √(2 * 9.81 m/s² * (0.42 m - 0.21 m))
v ≈ 2.0 m/s
When it hits the ground:
Initial potential energy = final kinetic energy
mgH = 1/2 mv²
v = √(2gH)
v = √(2 * 9.81 m/s² * 0.42 m)
v ≈ 2.9 m/s
Using a kinematic equation to check our answer:
v² = v₀² + 2a(x - x₀)
v² = (0 m/s)² + 2(9.8 m/s²)(0.42 m)
v ≈ 2.9 m/s
In order for the refrigerator not to tip over, the maximum acceleration of 1.86 m/s² must not be exceeded.
<h3>What is acceleration?</h3>
The term acceleration has to do with the rate at which velocity changes with time.
We have to take the moments at the tipping point of rotation as follows;
Clockwise moment = Anticlockwise moment
Hence;
F₂ * 1.58 m = F₁ * 0.67 m
The weight at half the width= 30 cm or 0.3 m
Height of refrigerator = 158 cm 0r 1.58 cm
Then;
m * a * 1.58 = m * 9.81 * 0.30
a = 1.86 m/s²
In order for the refrigerator not to tip over, the maximum acceleration of 1.86 m/s² must not be exceeded.
Learn more about acceleration: brainly.com/question/14344386
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