threw the ball as hard as he could to Priya It went so fast that Priya had to act quickly to catch it They kept playing for a long time Sometimes they missed the ball It fell to the ground or whizzed past the catcher’s shoulder When they got tired they moved closer together They gently tossed the ball to each other They didn’t have to throw as hard for the ball to reach the person catching It still followed a curved path through the air with each throw FRESH AIR Playing in the backyard or at the park can have health benefits Sunlight helps the body produce vitamin D The human body needs this vitamin in order to absorb calcium Calcium is a mineral found in foods It helps build healthy bones Vitamin D can also help prevent health issues such as cancer and bone problems Being outside increases physical activity Both sunlight and exercise improve people’s moods Spending time outdoors can even help people concentrate better 6
A GAME OF CATCH The basic process of a game of catch is very simple One person throws a ball to another person That person catches the ball and throws it back The different forces that make the ball move are more complicated Forces affect the motion of an object They cause an object to start moving stop moving or change its movement A girl may be throwing a ball to her brother She pulls her arm back while holding the ball Then her arm muscles move her arm and the ball forward quickly This action produces a force on the ball It sets the ball in motion When she lets go of the ball the girl is no longer putting any force on it But the throw did give the ball its starting velocity Velocity is the speed of an object combined with the direction in which the object is moving The ball has vertical velocity This is the speed at which the ball is moving up or down The ball also has horizontal velocity This is the speed at 7
Understanding the science of catch can help a person get even better at it which the ball is moving parallel to the ground toward the brother Once the ball is moving through the air it is called a projectile The laws of motion explain what happens to a projectile These laws were first described in 1687 by British scientist Isaac Newton Newton’s first law of motion says that forces change the way an object moves Forces can start or stop motion They may slow 8
an object down or speed it up They may change the direction in which an object is moving The ball keeps moving toward the boy But there is one main force acting on the ball when it’s in the air ball’s path through the wear gloves In fact they used That force is gravity Gravity pulls the ball down toward the ground It affects the air The girl’s throw caused the ball to travel forward and upward But gravity pulls on the ball Eventually gravity’s pull causes the ball to stop moving upward The ball’s path creates an arc All projectiles CATCHING MITTS Baseball players didn’t always to catch balls bare handed Ballplayers started wearing leather gloves in the late 1800s Additional padding helped prevent injury In 1920 a strip of material was added to the glove between the thumb and forefinger Catching the ball in that pocket meant the ball wasn’t hitting the player’s hand as hard It also gave players more The ball had a bigger spot to land in 9 and start falling down surface area on their hands
