Question

Question #53965

Answer 1

See explanation.

Explanation:

We know that:

`vec(v)=15 m/s`

`t=1s`

`n=2`

The fact that it takes `1s` to complete 2 revolutions implies that the period is `T=0.5s`

If we know the velocity we can calculate that:

`s=v*T=15*0.5=7.5`

The circle's circomference is `s=7.5`, so the radius is:

`r=s/(2pi)`

`r=7.5/6.28~~1.2`

The correct answer is `B`

Answer 2

The answer is B) 1.2 m.

Explanation:

The problem says that it takes `1` second to go two revolutions. If the object is traveling at `15m/sec`, or `15` meters per `1` second, two revolutions are `15` meters total (#15m=2 revolutions).

Divide the revolutions by 2 to get the meters per revolution:
`15/2 m=2/2 revolutions-> 7.5 m = 1 revolution`

1 revolution is equal to the circumference of the circle (`2pir`) created by the object's motion, so:

`1 rev = 7.5 m = 2pir`

`7.5m = 2pir`

`7.5/(2pi)m = (2pir)/(2pi)`

`r = 7.5/(2pi) m`

`7.5/(2pi) = 1.193`

Round this to get 1.2 m as your answer.