How far crayons will be moved forward?

The ruler is lying on two cylindrical crayons. Now imagine that you push one end of the ruler with your finger, causing it to move 4 cm forward. How far crayons will be moved forward?

A)4cm
B)8cm
C)2cm
D)1cm

Solution.

Let’s imagine that crayons are not moving but could rotate on the spot. The ruler and the desk under crayons will start to move. We could move ruler 2 cm forward and desk 2 cm backward, instead to move the ruler 4 cm. Now, if desk moves relative to crayons the crayons could move relative to desk and if we consider desk immobile the crayons will move 2 cm forward relative to desk.

The answer is (C)

Advertisements

One thought on “How far crayons will be moved forward?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s