Question

the sparks produced during sharpening of knife against a grinding wheel leaves the rim of the wheel tangentially. why? pls help me with this question

Answer 1

Grinding is a process which the pieces of metal from the edge of the knife to fall out and due to high temperatures on account of friction between the two surfaces the small pieces heat up and start to glow, producing sparks.
Now, the direction of motion of an object (or direction of its velocity) moving in a circular motion is always tangential to the circle (perpendicular to radius).
So, the sparks fly off the metal and will be propelled tangentially.

Answer 2

Answer:

In short, it is due to the inertia of direction.When the spark leaves the rim of wheel, it continues to move along the tangent which is due to the inertia of direction...

HOPE IT HELPS!!