# Search results

1. ### Angular momentum

Homework Statement The question involves a rotating disc, spinning about a vertical axis through its centre. We are given its angular speed, 20rpm and diameter 24cm. A piece of plasticine is dropped onto the disc (no torques are applied by this process). We are given its location relative...
2. ### Integration problem

Homework Statement I was given that \int \frac{m}{mgsin\alpha-kv} dv = -\frac{m}{k}ln(mgsin\alpha-kv) + C ..but I can't 'see' how this was done. Homework Equations The Attempt at a Solution My first thought is that this is somehow related to the fact that: \int...
3. ### Energy stored in springs

Homework Statement A particle (4m) is suspended from a fixed point by a spring of stiffness k and natural length l0. An identical 2nd spring is attached to this particle, and a mass (3m) is attached to its end. The system hangs vertically in equilibrium. Take the datuim of P.E. a in each...
4. ### Collision problem

Homework Statement Three particles, A,B,C all of equal mass m,collide at the origin. Prior to the collsion the particles are moving as follows: A has speed u in direction (1/sqrt(2))(-i-j) B has speed v in direction (sqrt(3)/2)i+(1/2)j C has speed w in direction -i After the collision all...
5. ### Find position vector from given velocity

Homework Statement A particle A of mass m is travelling on a horizontal surface with velocity 7i-4j and collides with a stationary particle of mass 3m at the origin of the co-ordinate system at time t=0 Find an expression for the position vector of A at time t<0 NB: There is more to...