已知物块重为<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/15bfe91bebeb4e94b3da9dc0579f4898.png?x-oss-process=image/sharpen,200"/>，放在地面上，物块与地面之间有摩擦，其摩擦角<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/be2b7f8f954d47ef90465e55b65b4b63.png?x-oss-process=image/sharpen,200"/>，物块受图示<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/ca67c54c1f5f44ceb93e90d6197ae00a.png?x-oss-process=image/sharpen,200"/>力的作用，若<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/33bd5899f97c4e228be26efd4614694d.png?x-oss-process=image/sharpen,200"/>，以下四种情况，哪一种说法是正确的。