# CBSE Class 11-Physics: Kinematics Problems: Questions and Answers-Part 1

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**Question:**

A nut comes loose from a bolt on the bottom of the elevator as the elevator is moving up the shaft at . The nut strikes the bottom of the shaft in sec

Find out the following:

a. How far from bottom of the shaft was the elevator when the nut fell off?

b. How far above the bottom of the shaft was the nut. sec after the fell off.?

c. How far above the bottom of the shaft was the elevator when the nut fell on the ground?

d. At what height above the bottom of the shaft, nut has zero velocity after the fell off?

e. what is the total distance travelled by nut in it motion after the fell off?

Given

**Solution:**

Here, first we need to read the question again and need to understand what is happening in the

Here nuts got loose and fall from elevator .it experience uniform gravitational acceleration during the motion and lift is keep moving up with constant velocity

The kinematics equation for constant acceleration would be of great help here

Now we need to decide origin and positive and negative axis.

We will choose here upward direction as positive

**Question**:

A nut comes loose from a bolt on the bottom of the elevator as the elevator is moving up the shaft at 3 m/s. The nut strikes the bottom of the shaft in 2 sec

Find out the following

a. How far from bottom of the shaft was the elevator when the nut fell off?

b. How far above the bottom of the shaft was the nut. sec after the fell off.?

c. How far above the bottom of the shaft was the elevator when the nut fell on the ground?

d. At what height above the bottom of the shaft, nut has zero velocity after the fell off?

e. what is the total distance travelled by nut in it motion after the fell off?

Given

A) Here the nut initially has the velocity of the elevator when it fell off.

Then

Now time to hit the ground

So

So, the bottom of the shaft was below when the nut fell off from elevator.

So, elevator was above the shaft when the nut fell off

**Question:**

A nut comes loose from a bolt on the bottom of the elevator as the elevator is moving up the shaft at . The nut strikes the bottom of the shaft in sec

Find out the following

a. How far from bottom of the shaft was the elevator when the nut fell off?

b. How far above the bottom of the shaft was the nut. sec after the fell off.?

c. How far above the bottom of the shaft was the elevator when the nut fell on the ground?

d. At what height above the bottom of the shaft, nut has zero velocity after the fell off?

e. what is the total distance travelled by nut in it motion after the fell off?

Given

B) Now Let calculate the nut displacement at

Substituting the values as same above

Thus, the nut was above its starting point. This makes sense if we remember the initial velocity as upward.

So, the total height above the bottom will be

**Question**:

A nut comes loose from a bolt on the bottom of the elevator as the elevator is moving up the shaft at . The nut strikes the bottom of the shaft in sec

Find out the following

a. How far from bottom of the shaft was the elevator when the nut fell off?

b. How far above the bottom of the shaft was the nut. sec after the fell off.?

c. How far above the bottom of the shaft was the elevator when the nut fell on the ground?

d. At what height above the bottom of the shaft, nut has zero velocity after the fell off?

e. what is the total distance travelled by nut in it motion after the fell off?

Given

C) Now the elevator perspective

upward

So, it will move 6m upward in .

So total height above the ground will be

From nut perspective

Or

So Total height above the bottom of shaft

f) Total distance travelled by