ANYONE UNDERSTAND THIS PHYSICS QUESTION

Question

Ima Bratt is at the park with her father. The 20.0 kg Ima is on a swing following the path as shown below. Ima has a speed of 0 m/s at position A and is a height of 3.0 m above the ground. At position B, Ima is 1.0 m above the ground. At position C (2.0 m above the ground), Ima ejects from the swing seat and travels as a projectile along the path shown. At point F, Ima is a negligible distance above the ground. Assume negligible resistance throughout the motion. How fast will Ima be going at point C?

a) 0 m/s

b) 1 m/s

c) 3 m/s

d) 4.5 m/s

e) 7.7 m/s

f) 14.1 m/s

g) 20 m/s

h) 22.2 m/s

l) don't be silly, it's none of these!

Answer 1

At point C, it doesn't matter what path Ima traveled, his speed is coming from the gravitational potential energy. If the resistance can be negligible, Ima's kinetic energy equals to the loss of gravitational potential energy:

.

With h = 1 meter and g=9.8 m/s², v = 4.427 m/s. So the closest option is (d).