why does a parachute slow you down
When an object is dropped it gets faster and faster as it falls. This happens because their weight (the force of gravity) pulls them down towards the centre of the Earth. As they fall through the air, they also experience an upward force called air resistance (drag). Objects with large surface areas, such as parachutes or shuttlecocks fall more slowly because they experience more air resistance. Frictional forces such as air resistance, friction and drag act
against the direction of motion, so tend to slow the object down. This fact is put to good use in the design of the parachute and shuttlecock. The size of frictional forces can be reduced by streamlining the object or lubricating any moving parts. A sports car is wedge-shaped to reduce air resistance and so increase top speed. Lorries and caravans have deflectors to reduce both air resistance and fuel consumption. A car with a roof box has increased air resistance and fuel consumption and a lower top speed. A downhill skier puts wax on the skis to reduce friction and so increase the top speed.
When objects fall through the Earth's atmosphere they get faster and faster until they reach a speed where the upwards force (air resistance) and downwards force (weight) equal each other. At this point the object travels at its fastest speed called terminal speed. What happens when you drop a coin and small feather at the same time? They both have a similar surface area but the feather weighs less so has a smaller force of gravity pulling it down. As the feather falls its upwards air resistance increases and soon equals its downwards weight, so it then travels at terminal speed. The coin is heavier and has to be travelling a lot faster before its air resistance is large enough to equal its weight. The astronaut, David Scott carried out a famous experiment on the Moon. He dropped a hammer and a feather at the same time and found they landed together. As there is no air on the Moon there is no air resistance. The only force on both the hammer and feather was the Moons gravity which made them both fall with the same acceleration. Do you have a bucket list?
If you've never heard that term before, it means a list of things you want to do, or in your Бbefore you kick the bucket! Would you like to visit the before you die? Put it on your bucket list! What about hiking the length of the or the? Those two trails are at the top of many bucket lists for sure. Another bucket list item is to do something and maybe even death-defying. How about jumping out of a thousands of feet above Earth? That's right! Skydiving is certainly a item near the top of many bucket lists. Have you ever thought about what it would be like to thousands of feet into the air and then jump into to feel what it's like to fly back toward Earth? We're sure it must be a rush unlike any other. Once you reach and Earth is getting closer and closer, you'll probably begin to about how quickly Earth is. Have no, though. All you need to do is pull the to your parachute. Once it unfolds, it'll slow your descent, allowing you to touch down on Earth rather than to a certain death! Exactly how does a parachute work?
If you've ever seen a parachute, you know it just consists of a large piece of with strings that attach it to a skydiver. There's no or propellers to lift you into the sky. How does a big piece of stop you from crashing into Earth? As you probably already know, the force pulling you toward Earth is gravity. Gravity pulls on all objects, yet some objects fall more quickly than others. Why is that? It all depends upon the properties of the falling object. Certain properties allow a falling object to fight its way past all those molecules of air standing between it and Earth. For example, a heavier object will tend to push past those pesky air molecules more quickly than a lighter one. A broad, flat object, on the other hand, will tend to fall more slowly than a narrow, round one. This is because a broad, flat object has a greater surface area for air molecules to push against. You can test this principle for yourself. Drop a regular piece of paper and a piece of paper crumpled up into a ball at the same time. Notice how much faster the crumpled piece of paper falls to the ground?
The force working against gravity that a parachute takes advantage of is called air resistance or drag. When a skydiver releases a parachute, it unfolds and quickly traps air molecules, increasing the amount of air resistance and slowing the skydiver to a safe descent speed. The larger the parachute, the more surface area it will have to trap air molecules and the greater its drag will be. This is why parachutes can be used to slow the descent of more than just skydivers. The military uses parachutes to deliver supplies and cargo to troops in remote areas. Parachutes are also used by drag racers to slow their cars at the end of a race. century, it's actually quite old. Historians point to late-15 -century manuscripts that contained drawings of a parachute-type device. also sketched a parachute prototype. Some believe the device existed hundreds of years before these sketches, though. Some historians believe Chinese acrobats may have used small parachute-like devices to perform falling stunts as early as 90 B. C.
- Views: 20
why does a projectile follow a curved path
why do we say that force is a vector quantity
why do we need to reduce friction
why do things fall at the same rate
why do objects fall at the same time
why do objects fall at the same rate
why do some objects fall faster than others