Why would a landslide be more likely on a steep mountain than on a gently sloping hill?

Ahot-air balloon is drifting straight downward with a constant speed of 2.40 m/s. when the balloon is 7.63 m above the ground, the balloonist decides to drop one of the ballast sandbags to the ground below. how much time elapses before the sandbag hits the ground?

Could someone . i have tried to solve myself but my calculation is off

Ms.hidalgo opens the door to her classroom. her classroom is 60 degrees and the air outside is 80. predict what will happen using your knowledge of how heat flows.