Answer:
Option C : 290 J
Explanation:
We can use conservation of energy to estimate the kinetic energy when the object hits the ground:
When the object is at its initial height of 15 meters, it velocity is zero (falls from this position), therefore the total energy it possesses is due to potential energy given by the expression:
Joules
At the moment the object hits the ground from its free fall, its potential energy is zero, while its kinetic energy must equal the rest. So at that moment the object's kinetic energy must be 294 Joules.
Answer:
a) (Positive), b) . The collision is not perfectly elastic.
Explanation:
a) The collision can be described by the Principle of Momentum Conservation and Principle of Energy Conservation:
The final velocity of the rock is:
b) The coefficient of restitution is the best criterion to distinguish elastic collsions from inelastic collisions, such criterion is the ratio of final energy of the system to initial energy of the system:
The collision is not perfectly elastic.
I believe it would be 70%
Explanation:
Given that,
Mass of the baseball, m = 0.147 kg
The initial speed of the baseball, u = 42 m/s
The final speed of the baseball, v = -54 m/s (in opposite direction)
We need to find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat. The change in momentum is given by :
We know that the impulse applied to it by the bat is equal to the change in momentum. So, the impulse is 1.764 kg-m/s.