A mass m is resting on a horizontal frictionless surface attached to a spring of spring force constant k . At time t = 0 , the mass is given a sharp blow, causing it to move the right with speed v . The next time the mass will have this speed is _________________ .
A: [img=87x39]1802eac7b3965ae.png[/img]
B: [img=91x46]1802eac7bbd36d7.png[/img]
C: [img=85x45]1802eac7c49f55d.png[/img]
D: [img=109x49]1802eac7d08bb09.png[/img]
A: [img=87x39]1802eac7b3965ae.png[/img]
B: [img=91x46]1802eac7bbd36d7.png[/img]
C: [img=85x45]1802eac7c49f55d.png[/img]
D: [img=109x49]1802eac7d08bb09.png[/img]
举一反三
- 设X,Y为两个随机变量,且[img=179x25]1803395d555effc.png[/img] , [img=226x25]1803395d61f1a43.png[/img] ,则[img=143x25]1803395d6f00057.png[/img]= ( ). A: 1/7 B: 3/7 C: 4/7 D: 5/7
- 设(X,Y)的分布律为[img=317x47]18039fa216cb556.png[/img]V=max(X,Y), 则P(V=1)等于 A: 1/7 B: 2/7 C: 3/7 D: 4/7
- 设(X,Y)的分布律为[img=317x47]18036e2ccb88792.png[/img]V=max(X,Y), 则P(V=1)等于 A: 1/7 B: 2/7 C: 3/7 D: 4/7
- 设(X,Y)的分布律为[img=317x47]18032d0bb35767f.png[/img]V=max(X,Y), 则P(V=1)等于 A: 1/7 B: 2/7 C: 3/7 D: 4/7
- 设(X,Y)的分布律为[img=317x47]1803e18fce4cd69.png[/img]V=max(X,Y), 则P(V=1)等于 A: 1/7 B: 2/7 C: 3/7 D: 4/7