Predict and observe changes in energy when objects collide

Help Questions

4th Grade Science › Predict and observe changes in energy when objects collide

Questions 1 - 10
1

Glen and his friend London are going sledding at a local park. There are two hills to choose from, "The Bunny Slopes," which are small hills and lots of flat surfaces, and "The Dragon," which is a steep hill and not for beginners. If London goes first and reaches the bottom and Glen crashes into him from behind on "The Dragon," what would happen to the motion of their sleds?

Screen shot 2020 06 23 at 8.39.55 am

Glen's sled would slow down or stop on impact, and London's sled would move forward.

Glen's sled would move forward on impact, and London's sled would stop.

Glen's sled would speed up on impact, and London's sled would move forward.

Glen's sled would speed up on impact, and London's sled would stop.

Explanation

If London is waiting at the bottom of the hill and Glen crashes into him there will be a change in the energy transferred when the collision takes place. When Glen hits the back of London his sled will stop or slow down while London's sled will be pushed forward and move. There is a transfer of energy from Glen to London that takes place when any two objects collide.

2

The diagrams below show a force on an object and its motion.

Screen shot 2020 09 10 at 8.24.56 am

Which diagram correctly shows the relationship between the force and the motion?

Diagram A

Diagram B

Diagram C

Diagram D

Explanation

The diagram that correctly depicts the relationship between force and motion is Diagram B. The force of an object is colliding with the white sphere and pushing it forward. The sphere will move in the direction it is being pushed. If two objects collide, energy will be transferred between both, and there will be a change in motion.

3

Karyssa is bowling with her friends, and she is looking at the pins when they each throw the ball. Looking at the pictures of the pins, Karyssa has to make a prediction of which ball she thinks had a greater speed upon collision and why?

Bowling, Pins, Falling, Alley, Lane, Fun Bowling, Bowler, Pins, Ball, Alley

In the first picture, the ball has a higher speed because the ball appears to be moving faster, and the pins are falling.

In the second picture, the ball has a higher speed because the pins are flying into the air, and more are falling.

In the first picture, the ball has a higher speed because the pins are falling sideways.

In the second picture, the ball has a higher speed because the player has a proper stance and looks strong.

Explanation

Both of these photos represent changes in energy during a collision. The ball is transferring energy to the pins when they make contact. Karyssa could predict based on the pictures and the positions of the pins, which she believed had a higher speed upon collision. When examining the photos, they both show pins falling and the ball making contact with the pins. The second photo shows the pins almost exploding at the end of the lane and flying through the air. A reasonable prediction could be made that this ball had higher speed upon collision because there was more energy transferred to the pins, and there was a more significant "reaction" when the crash took place.

4

In the image below, the arrows depict energy being applied to a triangle. This energy would cause the triangle to change positions. What is another name for a change in position?

Screen shot 2020 09 10 at 8.36.18 am

Location

Motion

Ovation

Deflation

Explanation

Another name for a change in position is "motion." Motion is the process or action of being moved or moving. The arrows are pushing against the triangle, and it will move in the direction of the energy being transferred.

5

When objects collide, the contact forces transfer energy so as to change the object's motions.

True

False

Explanation

The statement presented in the question is correct. If two objects collide, energy will be transferred between both, and there will be a change in motion. If I were to run into a friend at recess, we would both slow down and possibly fall backward or sideways due to the force of the impact. Objects can change speed, direction, or come to a complete stop because of a transfer of energy during a collision.

6

Two students are rolling a ball back and forth across the playground grass. Suddenly, the ball changes direction. When the students explore why this happened, they see that the ball hit a rock.

Which of these caused the ball to change direction?

A change in mass

A change in force

A change in volume

A change in gravity

Explanation

In this situation, the ball changed direction because it collided with the rock, and there was a change in force. If two objects collide, energy will be transferred between both, and there will be a change in motion. Objects can change speed, direction, or come to a complete stop because of a transfer of energy during a collision.

7

Marquise is at baseball practice. What force will most likely cause the baseball to change direction?

The batter's force on the ball with the bat

The batter's force on the ball as he misses

The catcher's force on the ball with his mitt

The pitcher's force on the ball as he throws

Explanation

The force of the ball hitting the bat will most likely cause the baseball to change direction. When the batter hits the ball, there is a force applied, and energy is transferred. The ball will move in the direction the force is pushing it. If two objects collide, energy will be transferred between both, and there will be a change in motion. Objects can change speed, direction, or come to a complete stop because of a transfer of energy during a collision.

8

Robert is trying to replicate the collision shown in the photograph below. Which ball would create the same change in energy?

Bowling, Bowler, Pins, Ball, Alley

Basketball, Play, Meadow, Grass, Green

None of these balls would create the same change in energy.

Baseball, Dirty, Sport, Ball, Old

Tennis Ball, Macro, Court, Yellow, Net

Explanation

If Robert is trying to recreate the same change in energy and have the same explosion of pins, none of these balls will work. Bowling balls are smooth, heavy, and built to create a change in energy when they collide with the pins. The baseball and tennis balls are small and light, so they will not transfer much energy to the pins. The basketball is larger but is also light and textured, so it will not roll as well and will not transfer the same amount of energy. It is more likely to knock pins down, but it will not create the dramatic explosion of pins crashing around the lane when struck.

9

True or False: The bowling ball in the picture will change directions because of the force applied by the pins.

True

False

Explanation

The statement in the question is false. The ball is transferring energy to the pins when they make contact, not vice versa. The force is being applied to the pins and will cause them to move and change direction while the ball continues on its path.

10

What does the term "collide" mean? Example: Jackson and Robbie were afraid to collide when their sleds crossed paths.

Hit with force while moving

An accelerator in which two beams of particles are made to crash

Pass close to each other without crashing

See someone you have not seen in a long time

Explanation

When objects collide, it means that they are hit with force while moving. Robbie and Jackson's sleds crossed paths and nearly collided or crashed into each other. When objects collide, there is a change or transfer of energy, and the object's motion can change. The objects may change direction, speed, or stop when they collide with something else.

Page 1 of 2
Return to subject