Answer:
8) 709.8875 J
9) The object is at 7.24375 m from the ground
10) Kinetic energy increases as the object falls.
Explanation:
We use the expression for the displacement h(t) as a function of time of an object experiencing free fall:
h(t) = hi - (g/2) t^2
hi being the initial position of the object (10m) above ground, g the acceleration of gravity (9.8 m/s^2), and t the time (in our case 0.75 seconds):
h(0.75) = 10 - 4/9 (0.75)^2 = 7.24375 m
This is the position of the 10 kg object after 0.75 seconds (answer for part 9)
Knowing this position we can calculate the potential energy of the object when it is at this height, using the formula:
U = m g h = 10kg * 9.8 (m/s^2) * 7.24375 m = 709.8875 J (answer for part 8)
Part 10)
the kinetic energy of the object increases as it gets closer to ground, since its velocity is increasing in magnitude because is being accelerated in its motion downwards.
The mechanical energy of an object is the sum of its potential and kinetic energy.
Because the ball is on the ground, its potential energy is 0.
Its kinetic energy is given by:
K.E = 1/2 mv²
K.E = 1/2 x 1 x 2²
K.E = 2 J
Mechanical energy = 2 + 0
Mechanical energy = 2 J
The answer is B.
1)the edges where two plates meet are plate boundaries.
2)a sudden slip on a fault triggers an earthquake as stress in the edge overcomes the tension that releases energy into waves that move through the surface of the earth and cause a shake.
3)motion of the ground, aftershocks, shuddering, trembling, wobbling, crashing, falling, breaking, and more
4) the outer layer of Earth is the crust (lithosphere) which is made up of hot molten rock and granite.
