6p1 Further Mechanics

Question 1

What are the letters and units in the equation
Ft = p

Answer 1

F - force (N)
t - impact time (s)
p - momentum (kgm/s)

Question 2

What is impulse

Answer 2

change of momentum and the equation is I = F x t

Question 3

What is the approach to solve problems of conserving momentum in two dimensions

Answer 3

resolve motion into components along perpendicular axes - solve resultant pair of problems in one dimension

Question 4

whats the difference between elastic and inelastic collisions

Answer 4

elastic is where both momentum and kinetic energy are conserved whereas inelastic is when only momentum is conserved as kinetic energy is converted into other forms

Question 5

which collision is it if objects stick together afterwards

Answer 5

inelastic collision

Question 6

how to derive the equation for non-relativistic particles kinetic energy

Answer 6

Ek = 1/2mv^2 with p = mv
sub v = p/m into the Ek equation
to get Ek = 1/2m(p^2/m^2)
and simplify for Ek = p^2/2m

Question 7

what do we know about an object moving in a circular path with a constant speed

Answer 7

constantly changing velocity as its constantly changing direction therefore the object is accelerating which is known as centripetal acceleration - we know from newtons first law that acceleration required a resultant force so an object moving in a circular path must experience a force which we call the centripetal force that acts towards the centre of the circle