Solar energy, wind energy, and hydroelectric energy are all renewable energy
The acceleration of a body in a gravitational field is independent of its mass. Both the stones will fall with the same acceleration through the same height and hence they will strike the ground simultaneously.
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Answer:
D
Explanation:i think but dont get mad if im wrong
Answer: F = 20 N
Explanation:
I will ASSUME that the fulcrum is at the center of gravity of the lever arm, This means that the lever arm itself creates no moment about the fulcrum because there is no moment arm for that particular force.
To solve, we sum moments about any convenient point to zero (zero because there is no acceleration in the F = ma equation)
The easiest convenient point is the fulcrum
30((90/2) - 15) - F(90/2) = 0
30(30) = F(45)
F = 900/45 = 20 N
Answer:
K.E = 30,000 J
Explanation:
Given,
The potential energy of the roller coaster car, P.E = 40000 J
The kinetic energy at height h/4, K.E = ?
According to the law of conservation of energy, the total energy of the system is conserved.
At height 'h', the total energy is,
P.E = mgh
K.E = 0
At height 'h/4', the total energy is
P.E + K.E = mgh
P.E = mgh/4
K.E = 1/2 mv²
Therefore,
mgh/4 + 1/2 mv² = mgh
gh/4 + v²/2 = gh
Hence,
v² = 3gh/2
Substituting in the K.E equation
K.E = 1/2 mv²
= 1/2 m (3gh/2)
= 3/4 mgh
= 3/4 x 40000
= 30000 J
Hence, the K.E of the roller coaster car is, K.E = 30000 J
