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Gre4nikov [31]
3 years ago
9

An object of mass 1.5 kg rests on a shelf where it has a gravitational potential energy of 7 joules. An object of mass 4.5 kg is

placed on the same shelf. What is the gravitational potential energy of this second object? A. 7 joules B. 10 joules C. 21 joules D. 31.5 joules
Physics
1 answer:
bija089 [108]3 years ago
6 0

Answer:

C. 21 Joules

Explanation:

We apply the formula to calculate the potential energy (Ep):

Ep=m*g*h

Where:

Ep : potential energy in Joules (J)

m :mass in kilograms (kg)

g  acceleration due to gravity  (m/s²)

h: height in meters (m)

Calculation of the height (h)

Ep = m*g*h

7 = (1.5 )*(9.8) *(h )

7 = (14.7) (h )

h = 7 /  (14.7)

h= 0.476 m

Gravitational potential energy of the second object

Ep = m*g*h

Ep = (4.5 )*(9.8) *(0.476 )

Ep = (4.5 )*(9.8) *(0.476 )

Ep = 21 J

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Answer:

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Explanation:

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Then:

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Other kinematic equation for uniform acceleration is:

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Since the window is falling and the air resistance is ignored, a = g (gravitational acceleration ≈ 9.8m/s²)

Replacing the known values we can set a system of two equations:

From (Vf + Vi)/2 = 300m/6.62s

(Vf + Vi) = 2 × 300m/6.62s

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From Vf = Vi + a×t

Vf - Vi = 9.8 (6.62)

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3 years ago
The moon is smaller and more dense than the Earth, and has less extreme temperature changes.
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Answer:

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Explanation:

From the question given above, the following data were obtained:

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Mass (m) =?

Next, we shall determine the velocity Leroy Burrell. This can be obtained as follow:

Distance = 1×10² m

Time = 9.5 s

Velocity =?

Velocity = Distance / time

Velocity = 1×10² / 9.5

Velocity = 10.53 m/s

Finally, we shall determine the mass of Leroy Burrell. This can be obtained as follow:

Kinetic energy (KE) = 3.40×10³ J

Velocity (v) = 10.53 m/s

Mass (m) =?

KE = ½mv²

3.40×10³ = ½ × m × 10.53²

3.40×10³ = ½ × m × 110.8809

3.40×10³ = m × 55.44045

Divide both side by 55.44045

m = 3.40×10³ / 55.44045

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BigorU [14]

Answer:

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