6
votes
4answers
106 views

What is difference between Inertial Mass and Gravitational Mass [duplicate]

I recently read that the mass we deal with in Equation $F=Ma$ is called inertial mass and the mass we deal with in $F=Mg$ is gravitational mass. Suppose I am taking a same ball in a free fall and in ...
1
vote
4answers
254 views

“Weight” of moving object in a car collision

From time to time I see safety warning about keeping loose items in your car. The last warning used a 2kg object, and claimed that if a collision occurred at $50{km\over h}$ it would have a weight ...
0
votes
2answers
2k views

Jumping in an elevator?

I've always been under the impression that jumping in an elevator wouldn't help at all, especially after reading a snippet of physics where Einstein said that free fall was identical to zero gravity. ...