- #1

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- 38

## Homework Statement

## Homework Equations

## The Attempt at a Solution

A) W.r.t. earth's frame,

After 2s , velocity of bolt = at = 1.2*2 = 2.4 m/s

distance traveled = (1/2) 1.2*2

^{2}= 2.4 m

Let's say that the bolt reaches the floor at time t.

Using s = ut + (1/2)at

^{2}

2.4 = 2.4t +(1/2)(-9.8) t

^{2}

Solving this equation doesn't give proper answer.

After leaving the car, the bolt goes up till its speed becomes 0 m/s. Let's say that this process takes the time t

_{1}and by this time the bolt travels a distance s

_{1}.

0 = 2.4 - 9.8t

_{1}

t

_{1}= 2.4/9.8 = 0.245

s

_{1}= 2.4* 0.245 + (1/2)(-9.8)0.245

^{2}=0.294 m

After the speed of the bolt becomes 0, the bolt starts falling down.

Let's say that the bolt takes time t

_{2}to reach the floor from now.

So,

s + s

_{1}= (1/2)9.8 t

_{2}

Solving this gives t

_{2}= 0.741s

**What is meant by free fall time ?**

t

t

_{2}= 0.741 s or t_{2}+ t_{1}= 0.986 s ?b) W.r.t. elevator,Taking t

_{2}as the free fall,

The displacement is

d = s + s

_{1}+

**[ {1.2*(2 + t**= 5.019 m where the bold part is distance traveled by the car in time t

_{1})} t_{2}+ (1/2) 1.2 * t_{2}^{2}_{2}

The distance is D = d+ s

_{1}= 5.019+0.294= 5.313 m,