A 30 kg child swings in a swing supported by one chain 3m long.The tension in th

Question

A 30 kg child swings in a swing supported by one chain 3m long.The tension in the chain at the lowest point is 400N.

a) find the child's speed at the lowest point

b)now suppose the speed of the child at the lowest point is such that when the child swings to her highest point, the chain is horizontal.What is the tension in the chain at this highest point?

c) what is the speed of the child at the lowest point in case b above?

I got a the speed is 3.26m/s, but so confuse b and c

could you explain, the final is coming thank you!!!!!

Explanation / Answer

a) at lowest point

T = m*g + m*v^2/L

400 = 30*9.8 + 30*v^2/3

==> v = sqrt( (400-30*9.8)/10 )

= 3.26 m/s <<<<<<<<------------Answer

b) T = m*v^2/L

= 30*3.26^2/3

= 106.2 N <<<<<<<<------------Answer

c) let v' is the speed at lowest point

Apply, v'^2 - v^2 = 2*g*L

v' = sqrt(v^2 + 2*g*L)

= sqrt(3.26^2 + 2*9.8*3)

= 8.33 m/s <<<<<<<<------------Answer

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.