Question

what is the average speed in metre per second if an extrusion press has a crank radius of 20 cm and 30 RPM

Answer 1

it is given that,

angular velocity of crank , $\omega$ = 30rpm = 30 × 2π/60 rad/s
= π rad/s

[note : rpm means revolution per minute , 1 revolution = 2π so, 1rpm = 2π/60 rad/s ]

and radius of crank , r = 20 cm

we know, linear velocity, v = $\omega r$

v = π × 20 = 20π cm/s

= 20 × 3.14 = 62.8 cm/s = 0.628 m/s



hence, average speed in metre per second is 0.628 m/s