054 SC 130 Physical science quiz five • Name:

  1. What does Newton's first law say that object will tend to do?
  2. If a moving object is losing momentum as time passes, then what does Newton's second law tells us is acting on the object?
  3. ____________________ Calculate the force required to bring a marble with a momentum p of 210 g cm/s to a stop in 0.5 seconds.
  4. ____________________ When all 67 kilograms of me falls off a RipStik, I accelerate towards the ground at 9.8 m/s² and then I hit the ground, exerting a force of 1400 Newtons on the ground. Calculate the counter-force that the ground exerts on me.
  5. ____________________ An elastic band stretches (displaces) a distance x of 5 cm when a 70 gram-force force f is applied. Calculate Hooke's constant k for the elastic.
  6. ____________________ Presume that the elastic band in the above problem is Hookean, that is, it is a linear elastic material. What will be the displacement x when a 210 gram-force force f is applied?
  7. A RipStik carrying a 32 kilogram rider accelerates from a speed of 1.6 m/s at 4.0 seconds to a speed of 2.0 m/s at 6.0 seconds. Calculate and write the acceleration of the RipStik and force required to generate that acceleration in the table.
time (s)velocity (m/s)acceleration (m/s²)Force (N)
4.01.6
6.02.0

Equations
[ d = ѵt ] [ ѵ = at ] [ d = ½at² ] [ d = ½gt² ] [ a= Δѵ Δt ] [ p = mѵ ] [ GPE = mgh ] [ KE = ½mѵ² ] [ F= Δp Δt ] [ F = ma ] [ F = −kx ]