In which of the following examples does the object have both kinetic and potential energy? Select all that apply.
1 answer:
Objects having both kinetic and potential energy:
water flowing downstream
a child swinging on a swing
a bouncing ball
a plane in flight at 30,000 feet
Explanation:
The kinetic energy of an object is the energy possessed by the object due to its motion. It is given by
where
m is the mass of the object
v is its speed
Therefore, an object has kinetic energy when its speed is non-zero (so, whenever it is moving).
The potential energy of an object is the energy possessed by the object due to its position in the gravitational field. It is given by
where
m is the mass
g is the acceleration of gravity
h is the heigth of the object relative to the ground
Therefore, an object has potential energy whenever it is located at a certain height above the ground.
So in this problem, the objects that have both kinetic and potential energy are:
a rock at the edge of a cliff --> NO, because the rock is at rest (so KE = 0)
water flowing downstream --> YES, because the water is moving AND it is at a certain height above the ground
a child swinging on a swing --> YES, because the child is moving AND it is at a certain height above the ground
a bouncing ball --> YES, because the ball is moving AND it is at a certain height above the ground
water behind a dam --> NO, because the water is at rest (so KE=0)
a car moving on a level road --> NO, because the car is at ground level (so PE=0)
a plane in flight at 30,000 feet --> YES, because the plane is moving AND it is at a certain height above the ground
a compressed spring --> NO, because the spring is at rest (so KE=0)
Learn more about kinetic and potential energy:
#LearnwithBrainly
You might be interested in