Q5 q19 choose the correct formula for the displacement d from the rest position of the object attached to the spring at time t.

t=0, d=0 so ans B is wrong

t=0, dd/dt <0 as it is propelled downward so ans C is wrong

ang vel = 2 / period

= 2 / 4.5

= 4 / 9

so D is the correct answer

triangle abc is translated (just moved) so it's rigid transformation.

because shape is preserved, it's also isomatric transformation.

because it's rigid and somatric transformation, so size would also preserved.

therefore, follwing options are applicable:

1) it is rigid.

2) it is isomatric.

3) the size is preserved.