A 5.0-kg rabbit and a 12-kg Irish setter have the same kinetic energy. If the setter is running at speed 4.9 m/s, how fast is th
1 answer:
You might be interested in
Explanation:
Let east direction is negative and west direction is positive. The acceleration of an object is given by :
Where
v is the final speed
u is the initial speed
t is the time taken
As the car decelerates, the final speed of the car is less as compared to the initial speed. As a result, its acceleration is negative. It means the car travels eastward and slows down. Hence, this is the required solution.
1) He has both potential and kinetic energy
2) Before the parachute opens, the potential energy decreases and the kinetic energy increases
Explanation:
1)
The gravitational potential energy of a body is the energy possessed by the object due to its position in a gravitational field, and it is given by:
where
m is the mass of the body
g is the acceleration of gravity
h is the height of the body above the ground
On the other hand, the kinetic energy of a body is the energy possessed by the body due to its motion; it is given by
where
v is the speed of the object
Here Mr. Leppold has both potential and kinetic energy before opening the parachute, because:
- It is moving at a certain speed, so , therefore he has kinetic energy
- He is at a certain height above the ground, , therefore he has potential energy
2)
The total mechanical energy of Mr.Leppold is the sum of the potential and the kinetic energy:
According to the law of conservation of energy, in absence of air resistance, this quantity remains constant.
During the fall, the height of Leppold decreases: this means that as decreases, the potential energy decreases too.
However, the total energy E must remain constant: therefore, this means that the kinetic energy KE must increase, and this occurs because the speed of Mr. Leppold increases as he falls.
Learn more about kinetic and potential energy:
#LearnwithBrainly