Answer:
The fulcrum of the metre stick is at the 40 cm mark
100 g * 10 cm = 1000 g-cm clockwise torque
x * 30 cm = 1000 gm-cm = counterclockwise torque for balance
X = 1000 / (40 -10) = 1000 / 30 = 33.3 gm at 10 cm to balance
All look good, but i’m pretty sure 7 should be velocity
KE= (1/2) mv²
So, the variables we need to include in our question would be a varable for a mass(m) of an object at some velocity(v).
My Answer:
(This is just an example question, yours can be different)
What is the Kinetic Energy experienced by an bouncy ball rolling at 7m/s (that's your velocity) across a frictionless surface that has a mass(m) of 10 grams?