题目内容

A professional skier reaches a speed of 56 m/s on a 30° ski slope. Ignoring friction, what was the minimum distance along the slope the skier would have had to travel, starting from rest（）

A. 110 m
B. 160 m
C. 320 m
D. 640 m

查看答案

搜索结果不匹配？点我反馈

更多问题

A girl and her bicycle have a total mass of 40.0 kg. At the top of the hill her speed is 5.0 m/s, and her speed doubles as she rides down the hill. The hill is 10.0 m high and 100 m long. How much kin

A. 2 420 J
B. 1 500 J
C. 2 000 J
D. 3 920 J
E. 4 920 J
F. 1 920 J

The quantity of work equal to one joule is also equivalent to which of the following（）

A. watt
B. watt /s
C. watt∙s
D. watt /s^2

A Hooke’s law spring is mounted horizontally over a frictionless surface. The spring is then compressed a distance d and is used to launch a mass m along the frictionless surface. What compression of

A. 1.41 d
B. 1.73 d
C. 2.00 d
D. 4.00 d
E. 5.30 d
F. 6.10 d

A 550 N physics student stands on a bathroom scale in an 850 kg （including the student） elevator that is supported by a cable. As the elevator starts moving, the scale reads 450 N. The acceleration of

A. 17.82m/s^2, upward
B. 17.82m/s^2, downward
C. 1.782m/s^2, upward
D. 1.782m/s^2, downward
E. 178.2m/s^2, downward
F. 178.2m/s^2, upward