Hermes1
Banned
- Joined
- Oct 4, 2010
- Messages
- 1,282
- Gender
- Male
- HSC
- 2011
A particle of mass m moves in a straight line away from a fixed point O in the line, such that at time t its displacement from O is x and velocity is v.
At time t = 0, x = 1 and v = 0. Subsequently the only force acting on the particle is one of magnitude mk/x^2 where k is a positive constant in a direction away from O. Show v cannot exceed
Can you guys check my working bcuz i just started mechanics and im a bit unsure of what is legit:
 = \frac{k}{x^{2}})
subbing in the conditions given you get c = k
as x approaches infinity
a approaches 0
v approaches
therefore limiting value of velocity is root (2k)
and v cannot exceed root (2k)
also in resisted motion how do you decide when to have the force as positive or negative. so if the projectile is being thrown upwards would you say that the upward direction is positive and the resistive force is then negative?
At time t = 0, x = 1 and v = 0. Subsequently the only force acting on the particle is one of magnitude mk/x^2 where k is a positive constant in a direction away from O. Show v cannot exceed
Can you guys check my working bcuz i just started mechanics and im a bit unsure of what is legit:
subbing in the conditions given you get c = k
as x approaches infinity
a approaches 0
v approaches
therefore limiting value of velocity is root (2k)
and v cannot exceed root (2k)
also in resisted motion how do you decide when to have the force as positive or negative. so if the projectile is being thrown upwards would you say that the upward direction is positive and the resistive force is then negative?
Last edited:
