P6 Energy Conversion Topic

Wooden Block Sliding Down the Ramp

This science revision note aims to help your child:

– Understand how potential energy changes at different positions

– Take note of the clues in the question (have you spotted them?)

– Take note of the scientific keywords

 

But before you read on, you might want to download this entire revision notes in PDF format to print it out for your child, or to read it later.

This will be delivered to your email inbox.

Ava set up a slope on the ground as shown below. The slope is held up by 3 identical blocks. P, Q and R are points on the slope. Ava places a wooden cube at Point Q, then releases it to let it slide down the slope. The wooden cube stops at Point S on the ground.

Which of the following statements is true?

1) The wooden cube has more gravitational potential energy at Point R compared to Point Q.

2) The wooden cube has the most kinetic energy at Point R compared to the other points.

3) If the setup had 2 identical blocks instead of 3, the wooden cube would have slid further than Point S.

4) If the wooden cube had been released at Point P instead of Point Q, the wooden cube would have slid down slower.

 

STEP 1

Identify the energy conversion taking place.

  1. At Point Q, when Ava places the wooden cube there, the cube has gravitational potential energy.
  2. When she releases the cube, gravitational potential energy is converted to kinetic energy in the cube as it slides down the slope
  3. The cube stops at Point S when all kinetic energy is converted to heat and sound energy

Hence, the energy conversion of the wooden cube is:

Gravitational potential energy –> kinetic energy –> heat energy and sound energy

 

 

STEP 2

Let’s evaluate each option to determine if it is true by considering energy conversion.

 

OPTION 1

“The cube has more gravitational potential energy at Point R compared to Point Q.”

Point R is lower than Point Q, so gravitational potential energy in the wooden cube is converted to kinetic energy as the wooden cube slides from Point Q to Point R. Hence, the wooden cube has less gravitational potential energy at Point R compared to Point Q.

This option is wrong.

 

OPTION 2

“The cube has the most kinetic energy at Point R compared to the rest of the points.”

As mentioned in the previous point, gravitational potential energy in the wooden cube is converted to kinetic energy as the wooden cube slides from Point Q to Point R.

Hence, there is more kinetic energy in the cube at Point R compared to Point Q. The cube does not reach Point P so we can ignore this point for this option. At Point S, the wooden cube comes to a stop (It’s stated in the question!) meaning there is no kinetic energy in the wooden cube. Thus, the wooden cube does have the most kinetic energy at Point R compared to the rest of the points.

This option is correct!

 

OPTION 3

“If the setup had 2 blocks instead of 3, the cube would have slid further than Point S.”

The current setup has 3 identical blocks holding the slope up. If there were 2 blocks instead, the slope would have been less steep, with Point P being lower than the current setup. This would mean that Point Q would also be lower. The wooden cube would thus have less gravitational potential energy as it starts at a lower height. Less gravitational potential energy will be converted to less kinetic energy as the wooden cube slides down the slope, so it would take a shorter distance for all the kinetic energy to be converted to heat and sound energy for the cube to stop. The wooden cube would thus travel a shorter distance, not even reaching Point S.

This option is wrong.

 

OPTION 4

“If the cube had been released at Point P instead of Point Q, the cube would have slid down slower.”

Point P is higher than Point Q. If the wooden cube is placed at Point P, it would thus have more gravitational potential energy compared to at Point Q. More gravitational potential energy will be converted to more kinetic energy when the wooden cube is released. More kinetic energy means the wooden cube can slide faster.

This option is wrong.

 

 

FINALLY, choose the correct answer.

The answer is 2.

 

Take note of the explanations for each option. 

Common keywords written out are:

– The types of energy

– Object(s) that has that form of energy.

– Converted to

 

These keywords will help your child answer the science open-ended questions relating to energy conversion. 🙂

You can download this revision note so your child can revise them anytime.

This will be delivered to your email inbox.

 

 

Click here for other primary science revision notes >>> https://scienceshifu.com/primary-6-science-revision-notes/

P3 P4 Science GuideBook

Purchase this P3 P4 Science Revision Guidebook for your child

 

Included inside this ebook:

Over 120 pages of detailed science concepts provided

14 challenging exam-based questions for your child to apply the science concepts.

– Detailed explanation videos of 6 exam-based questions

 

Click on the button below to find out more about this ebook

Join the ScienceShifu Channel to get the latest learning tips.

 

Benefits of joining ScienceShifu on Telegram:

– Be the first to receive science revision notes from us

– Receive special promotions on all our online courses. 

 

Click on the button below to join the ScienceShifu channel:

Follow the ScienceShifu Instagram Channel to learn more science concepts

 

Benefits of joining Instagram:

– Watch out for interesting posts from ScienceShifu explaining science concepts

– Short videos where I will be going through past year exam questions

 

Click on the button below to follow the ScienceShifu Instagram Channel:

Talk again soon!

Andy Ling – Founder of ScienceShifu.com

Guiding your child to be the master of science concepts

 

Download our free revision notes to help your child prepare for the crucial exams.

Be part of our mailing list to receive the latest offers and learning tips from us.

Leave a Reply

Your email address will not be published. Required fields are marked *

*