Year 3 Science worksheet on friction, explaining the concept with examples and questions.

Problem: Friction Worksheet Analysis and Solutions

The worksheet focuses on the concept of friction, its effects, and how it works in different scenarios. Below are the solutions to each question with detailed explanations.

---

#### 1. To create friction, do we need one or two surfaces?
- Answer: Two surfaces.
- Explanation: Friction is the force that occurs when two surfaces slide or rub against each other. It requires at least two surfaces to interact. For example, a shoe sliding on the ground or a ball rolling on a surface.

---

#### 2. Does friction work in the same direction or opposite direction?
- Answer: Opposite direction.
- Explanation: Friction always acts in the direction opposite to the motion or intended motion of an object. This is why it slows down moving objects. For example, if you push a box across the floor, friction acts in the opposite direction to resist the motion.

---

#### 3. Which shoe sole would create the most friction in the playground, a or b?
- Answer: Shoe sole a.
- Explanation: The image shows two shoe soles:
- a: A textured or patterned sole.
- b: A smooth sole.

Textured or patterned soles (like those on trainers) increase the contact area and grip between the shoe and the surface, creating more friction. Smooth soles have less grip and thus create less friction. Therefore, shoe sole a would create more friction.

---

#### 4. Would a toy car when pushed go further on sandpaper or tin foil?
- Answer: Tin foil.
- Explanation: Sandpaper has a rough surface, which creates high friction. This high friction would slow down the toy car quickly. On the other hand, tin foil is smoother, resulting in lower friction. Lower friction means the toy car would travel farther before coming to a stop.

---

#### 5. Why are ice skate blades made of metal?
- Answer: Ice skate blades are made of metal because metal has very little friction with ice.
- Explanation: Metal surfaces have a low coefficient of friction compared to other materials. When ice skates glide on ice, the metal blades reduce friction, allowing the skater to move smoothly and efficiently. If the blades were made of a material with higher friction, skating would be much harder and slower.

---

#### 6. Why do trainers have a pattern on them?
- Answer: Trainers have a pattern on their soles to increase friction.
- Explanation: The pattern on the soles of trainers (e.g., tread or grooves) increases the contact area and grip between the shoe and the ground. This additional friction helps prevent slipping, especially on uneven or wet surfaces. It enhances traction and stability during activities like running or playing sports.

---

#### 7. Which surface has the least friction, glass or grass?
- Answer: Glass.
- Explanation: Glass is a smooth surface, which generally has lower friction compared to rough surfaces. Grass, on the other hand, is rough and irregular, providing more resistance to movement. Therefore, glass has the least friction.

---

Final Answers:

1. Two surfaces
2. Opposite direction
3. a
4. Tin foil
5. Metal has very little friction with ice.
6. To increase friction and prevent slipping.
7. Glass

---

Final Answer Box:
\boxed{1. \text{Two surfaces}, 2. \text{Opposite direction}, 3. \text{a}, 4. \text{Tin foil}, 5. \text{Metal has very little friction with ice.}, 6. \text{To increase friction and prevent slipping.}, 7. \text{Glass}}