## An acorn falls from a tree and lands on the ground

In a panic, you slap on the brakes and skid a short distance on a smooth, level lane. What distance would the car have skidded if you had been driving twice as fast in the same conditions?
A ball falls from the top of a building to the ground below, through the air (no air friction). How does the potential energy (U) at the top of the building equate to the kinetic energy (K) just before striking the ground?
A ball falls from the top of a building to the ground below, passing through the air (there is air friction). How does the potential energy (U) at the top of the building equate to the kinetic energy (K) just before striking the ground?
A 10-g dart is fired from a spring-driven dart gun. A force of 20 N is applied over a distance of 5.0 cm to cock it. What is the pace at which the dart will leave the gun, assuming the spring has no mass?
An arrow with a mass of 20 g is fired horizontally into a bale of hay at a speed of 60 m/s. It goes down to a depth of 20 cm before coming to a halt. What is the average force acting on the arrow to stop it?

## An acorn falls from a tree which of the following statements is true

Explanation: Potential energy can be used to solve problems. Remember that since your height and gravity are going in the same direction, they must have the same symbol (downward). Using an absolute value or make them both negative.
We know from energy conservation that. This means that at the bottom of the slope, all of the potential energy at the top is transformed to kinetic energy. Potential and kinetic energy can be substituted in the equations.
Explanation: The ball begins with both potential and kinetic energy in this dilemma. There will be no potential energy at the maximum velocity stage. Due to energy conservation, we can solve by making the initial and final energies equivalent.
Explanation: At first, the book only has potential energy. All of the potential energy will be transformed to kinetic energy just before it reaches the earth. To make the initial and final energies equal, we may use the law of conservation of energy.
Explanation: The book begins with only potential energy. All of the potential energy would have been transformed to kinetic energy just before it reaches the earth. Due to energy efficiency, the two values would be identical.

### An apple falls from a tree compare its kinetic energy k to its potential energy u

Take, for example, gravitational potential energy (PE). This form of energy refers to an object’s energy as a function of its height in relation to a reference level, such as the top of a hill or a rooftop. Kinetic energy (KE) is the energy associated with an object as a result of its speed or motion, such as when throwing a ball or sliding a box across the floor. The formulas can be found below.
Let’s say you climbed to the top of a tree in your backyard and planned to throw acorns at passers-by. We’ll pretend there’s no air resistance (we live in a vacuum world) and that the system’s total mechanical energy is constant.

### How does the work needed to stretch a spring 2 cm compare to the work needed to stretch it 1 cm?

Take, for example, gravitational potential energy (PE). This form of energy refers to an object’s energy as a function of its height in relation to a reference level, such as the top of a hill or a rooftop. Kinetic energy (KE) is the energy associated with an object as a result of its speed or motion, such as when throwing a ball or sliding a box across the floor. The formulas can be found below.
Let’s say you climbed to the top of a tree in your backyard and planned to throw acorns at passers-by. We’ll pretend there’s no air resistance (we live in a vacuum world) and that the system’s total mechanical energy is constant.