Energy Transfer in Collisions Chapter Notes | Science for Grade 4 PDF Download

Introduction

When one object strikes another, a collision occurs, resulting in the transfer of energy from one object to the other. Energy is the capacity to perform work, or simply put, it enables things to happen. The quantity of energy transferred in a collision is determined by the mass and velocity of the moving object.

Collisions happen all around us

• Each day, we witness and encounter countless collisions. A collision might be as soft as a puppy’s lick on your face or as striking as a wrecking ball crashing into a structure. 
• Collisions are a common part of daily life. Objects slip from hands and hit the ground. Drumsticks strike drums to produce sounds. Sports are filled with collisions. 
• Consider baseball: The batter aims to hit the ball with the bat. At the moment of contact, energy transfers from the swinging bat to the ball, sending it soaring.

Energy transferred when  two objects collide

• Do you like to go bowling? When you roll the ball, you transfer energy from the moving ball to the bowling pins. 
• Bumper cars provide another clear example. Typically, all the cars are in motion. When one bumper car collides with another, energy is transferred, causing the passengers to feel a shift in their movement. The cars might come to a stop or change direction as a result of the collision’s impact.

The faster an object is moving, the more energy it can transfer

• Faster-moving objects transfer more energy during collisions.
• In a demonstration, a woman and man in bubble suits collide to show energy transfer.
• Energy transfer in collisions depends on an object’s speed, with faster speeds causing greater impact.
• For Example: Dr. Jeff’s mom knocks Izzy farther by running faster, transferring more energy upon collision.
• This principle applies to car safety: high-speed car crashes result in more severe damage due to greater energy transfer.
• Speed limit signs are used to reduce crash severity and enhance driver safety.

The heavier an object, the more energy it can transfer

• Objects with greater mass possess more energy. This is why collisions between trucks and cars are so destructive to cars. In a crash, the substantial energy from the heavy truck is transferred to the lighter car.  
• Have you observed that the largest football players are the hardest to stop? When a 300-pound lineman tackles a 100-pound quarterback, the quarterback is easily overpowered. 
• In animal territorial disputes, the larger animal typically prevails. Its greater mass allows it to transfer more energy during a collision, giving it an advantage.