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" Dim Lights Share a clea.nr URL: Hide Comments, Favorites, Suggested Videos, etc. There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force. Subscribe 109 videos 32,519 Like Add to Share Uploaded by 1veritasium on Feb 7, 2011 There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force. 320 likes, 14 dislikes Show more Uploader Comments ( 1veritasium ) Actually, it is the friction which is causing difficulty in moving the car. Ideally if there is no friction, whether rolling or sliding, even the slightest of the force would make the car move. You could actually be able to move the car with a push of your little finger if there is no friction at

"http://yt.cl.nr/iQOHRKKNNLQ" In this segment I ask why astronauts in the space station are weightless. The most common answer is because there is no gravity in space. But of course there is gravity in space, especially where the space station is located (only about 400km from Earth's surface). So astronauts still experience a gravitational pull - it's just that they and the space station are in free fall so they are accelerating together towards the Earth. The space station doesn't crash into the Earth because of its orbital velocity - it's going 28,000 km/h so as it falls, the Earth curves away from it.

"http://yt.cl.nr/_mCC-68LyZM" If you drop a heavy object and a light object simultaneously, which one will reach the ground first? A lot of people will say the heavy object, but what about those who know both will land at the same time? What do they think? Some believe both objects have the same gravitational pull on them and/or both fall to the ground with the same constant speed. Neither of these things is true, however. The force is greater on the heavy object and both objects accelerate at the same rate as they approach the earth, i.e. they both speed up but at the same rate.

The scale of the experiment matches the scale of the intellectual leap achieved. A huge apparatus, 27 kilometres in circumference, buried 100 metres below the French-Swiss border near Geneva, accelerated particles in a near-perfect vacuum to speeds just below that of light and measured the effect of their collisions. Minute variations in energy released prove the existence of the Higgs boson, which had been postulated in theory by Peter Higgs in 1964 to explain the mass of elementary particles. Wednesday's discovery, published by two separate groups of researchers working in isolation from each other, can be compared with the discovery of DNA, or Einstein's theory of relativity, or the splitting of the atom. Achievements such as those are like peaks in a mountain range. They draw the world's attention, but really it is the great mass of the range itself that holds the peaks up which has more significance. Without the massive bulk below, the peaks would not reach so high. For science that great mass is a huge amount of lead-up work. The standard model of particle physics is the work of many hundreds of researchers, only one of whom was Professor Higgs. That achievement sits within the millions of achievements of the wider research effort of the whole science community. And that is enclosed, too, within the wider community which understands and supports what science has achieved and can achieve. Read more: http://www.smh.com.au/opinion/editorial/science-gets-a-chance-to-show-the-way-20120706-21mf2.html#ixzz21rjUGfs0