Need help on this applied math Q!!!!

overpower

A smooth sphere of mass 4kg collides obliquely with another smooth sphere of mass 'm' which is at rest. After the impact the two spheres move at right angles to each other. if the coefficient of restitution was 4/7,calculate the value of 'm'

Mwalimu

overpower wrote: »

A smooth sphere of mass 4kg collides obliquely with another smooth sphere of mass 'm' which is at rest. After the impact the two spheres move at right angles to each other. if the coefficient of restitution was 4/7,calculate the value of 'm'

I assume you are familiar with the laws governing collisions.:rolleyes: Let A be the angle which the 4 kg mass makes with the line joining the centres at the point of impact (make this line the i axis). If its speed before impact was u, resolve this into i and j components using angle A. After the collision, the 4 kg mass moves perpendicular to this line (and thus along the j axis). The j component of its velocity is not affected by the impact, so this remains as it was.;) Its i component of velocity goes to zero as a result of the impact. The mass m moves with velocity v along the i axis after impact (can you explain why?) and so has no j component of velocity. This should give you enough to set out the two equations (momentum before/after, and restitution) which you can then simplify to find the required value of m.:)

rwg

overpower wrote: »

A smooth sphere of mass 4kg collides obliquely with another smooth sphere of mass 'm' which is at rest. After the impact the two spheres move at right angles to each other. if the coefficient of restitution was 4/7,calculate the value of 'm'

5.5