That's just the way the pulleys are strung. For every 3 units of motion of the string being wound by the motor, the lifted mass rises 1 unit.AN630078 said:
That's the velocity of the mass m, not the rate at which the reel is winding the string.
Oh ok thank you very much for your reply. I did not know that, so is it because there are three pulleys in this system to lift the mass by 1 unit. But for example if there were only two pulleys for the string to be wound around would the velocity be found by v=2u?Halc said:
It is not so much the number of pulleys but the number of strings between the pulleys. There are 3 strings pulling up on m, and the force needs to balance. So there is 980 N pulling down, so each string must be pulling up at 327N. The 333 answer seems to assume a round 10 m/sec gravitational acceleration.AN630078 said:
Oh ok I think I understand it far better now Thank you for your helpHalc said:
The formula for solving for v using W and r is v = W/r, where v is velocity, W is work, and r is distance.
The units for W should be in joules (J) and the units for r should be in meters (m) in order to get the correct unit of velocity, meters per second (m/s).
The relationship between W, r, and v can be understood as the amount of work done (W) over a certain distance (r) resulting in a specific velocity (v).
If the value of W is negative, it means that work is being done in the opposite direction of the displacement (r). This will result in a negative velocity, indicating that the object is moving in the opposite direction of the applied force.
No, the formula can only be used in situations where the force applied (W) is constant and the object is moving in a straight line. It cannot be used for situations with varying forces or curved motion.
