| Wow! It
certainly isn't as easy to get to grandma's house as it used to be!
Sally thought she could get across the raging river by swinging on this 10-m rope. She ran at it and grabbed hold, but she wasn't running fast enough. Her amplitude is too small. Sally's smart, though; she knows that pumping (as on a swing) she can increase the amplitude and make it across. However, she is worried about being late; grandma worries about wolves! She needs to know how much time it takes to swing back and forth. Can you help her? (I certainly hope so, 'cause that's what this quiz is about!) |
The time for one back and forth swing
would be its period.
The period of a pendulum depends on its length and the value of gravitational acceleration. T = 2pi(l/g)1/2 so (using g = 10 m/s2), T = 2(3.14)(10 m / 10 m/s2)1/2 = 6.28 s |