普物問題(請高手解答一下)

The skiing duo of Brian(80kg) and Ashley(50kg) is always a crowd pleaser.In one routine

Brian

wearing wood skis

starts at the top of a 200-m-long

20。

slope.Ashley waits for him halfway down.As he skis past

she leaps into his arms and he carries her the rest of the way down.What is their speed at the bottom of the slope?這題我解了很久也跟同學討論過了可是就是跟答案不同是哪裡出錯了?答案大於30m/s都是錯的小於20m/s也是錯的20。

=20度
sin 20度=0.34202Va^2 = 2 a s = 2 * 9.8 * 0.34202 *100 ==