D. Short answer type-l questions:
1. What are fluids? Name two fluids.
2. What is streamlined shape? Give one example which has streamlined shape.
3. Why wheels are very useful?
4. What are lubricants? How they affect the friction?
5. Why do gymnasts apply a coarse substance on their hands?
Answers
Answer:
1) A substance which can flow is called fluid. The common fluids are juice, water, and soup.
2) The shape of the body is said to be streamlined if the body tapers at both ends. Examples: Fishes have streamlined bodies so that they have less resistance when swimming in water. Birds have a streamlined body to make their flight easier through the air. Snakes have a streamlined body to assist them move forward.
3) Wheels are so useful because it is the most important part of vehicles for transportation. For example, before the wheel was invented, people had to walk, carry very heavy things, and had to use a boat to get over seas. ... Also, you can't go one day without seeing a wheel.
4) A lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.
5) Gymnasts apply a coarse substance to their hands for a better grip.
pleae like if it is helpful
Answer:
1.the substances which can flow easily are called fluids. all liquids and gases are fluids . example - water, oil, air etc.
2.the shape of the body is said to be streamlined if the body tapers at both ends. Examples: Fishes have streamlined bodies so that they have less resistance when swimming in water. Birds have a streamlined body to make their flight easier through the air. Snakes have a streamlined body to assist them move forward.
3.But the reason that the wheel is a very important and useful technology is because of its mechanical advantage. The wheel gains its mechanical advantage because it reduces friction. Friction is the attraction between two objects that are touching each other. It keeps them from separating easily.A wheel reduces friction by allowing the contacting surfaces to roll rather than to drag or slide over each other. By reducing friction, a wheel can enable you to use less force to move an object. The less force you use to move an object, the easier your work becomes. 4.lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. 5.Gymnasts apply a coarse substance to their hands for a better grip.