• Question: What is the difference between the gravitational pull and up thrust?

    Asked by to Jane, Iain, Chris, Anna, Nick on 14 Mar 2014. This question was also asked by .
    • Photo: Anna Middleton

      Anna Middleton answered on 14 Mar 2014:

      Hi cass1b0y….right, I’m going to ask my husband, he is an military RAF engineer….I’ll get back to you……!

    • Photo: Chris Cole

      Chris Cole answered on 14 Mar 2014:

      The difference is between the two is whether you stay stuck to the ground or not.

      If gravitational pull is greater than up thrust – then you stay stuck to the ground. e.g. when you’re stood still.

      If up thrust is greater than gravitational pull – then you leave the ground. e.g. when you jump. How far you leave the ground is dependent on how big the thrust is. You may be able to jump a metre or two – more with a trampoline. With a powerful rocket you can leave Earth.

Comments

  • Photo: Anna

    Anna commented on :

    Right o, this is what my husband said….
    “Gravity is a natural occurring acceleration towards the centre of the earth caused by the earth’s mass. Up thrust in a man made force explained in aerodynamics by the effect of negative pressure on the upper surface of a wing and positive pressure on the lower surface of a wing giving rise to ‘up thrust,’ commonly known as lift.”

    Not sure I totally understand this myself! Let me know if it doesn’t make sense and I’ll get him to translate!