- 4

- 0

**1. choose one of the options to answer the following and please explain, thank you**

Suppose a child's natural frequency of swinging is once each 4 seconds.

For maximum amplitude the man should push at a rate of once each

2 seconds 4 seconds 8 seconds

If the man in previous question pushes in the same direction twice as often, his pushes

will be effective will not be effective

because

the swing will be pushed twice as often in the right direction

every other push will oppose the motion of the swing

Based on this swing example, a 440 hz-tuning fork could NOT be forced into vibration by a sound of

220 hz 440 hz 880 hz

Suppose a child's natural frequency of swinging is once each 4 seconds.

For maximum amplitude the man should push at a rate of once each

2 seconds 4 seconds 8 seconds

If the man in previous question pushes in the same direction twice as often, his pushes

will be effective will not be effective

because

the swing will be pushed twice as often in the right direction

every other push will oppose the motion of the swing

Based on this swing example, a 440 hz-tuning fork could NOT be forced into vibration by a sound of

220 hz 440 hz 880 hz

**2. none**

**3. not yet**