a wire of length 2m supports a bowling bowl of mass 4kg in a vertical position at point X (the bottom of the circle). The ball is moved to point Z (90 degrees anti clockwise from X) and reeleased. calculate the tension in the wire as the ball moves through point X.
thanks for your help! :)
thanks for your help! :)
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Kinetic energy gained at lowest position = gravitational potential energy lost
½mv² = mgh
v² = 2gh = 2 x 9.8 x 2 = 39.2m²/s² (we need v², not v in the next step)
At the lowest position, the centripetal force = mv²/ r = 4 x 39.2 / 2 = 78.4N
Remember, in circular motion, the centripetal force is just another name for the total force towards the centre.
And for circular motion take positive as towards the centre.
Resultant force on ball = tension - weight = T - mg. This is the centripetal force.
T - (4x9.8) = 78.4
T = 117.6N
= 120N to 2 significant figures.
½mv² = mgh
v² = 2gh = 2 x 9.8 x 2 = 39.2m²/s² (we need v², not v in the next step)
At the lowest position, the centripetal force = mv²/ r = 4 x 39.2 / 2 = 78.4N
Remember, in circular motion, the centripetal force is just another name for the total force towards the centre.
And for circular motion take positive as towards the centre.
Resultant force on ball = tension - weight = T - mg. This is the centripetal force.
T - (4x9.8) = 78.4
T = 117.6N
= 120N to 2 significant figures.
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You have misunderstood centripetal force. It is not some sort of separate force. It is the resultant of weight (W) and tension (T). T and W are the ONLY forces.
You have misunderstood centripetal force. It is not some sort of separate force. It is the resultant of weight (W) and tension (T). T and W are the ONLY forces.
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