Question

What is the safest speed of motion of a cyclist in a death well?
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Answer 1

Answer:

When the motorcyclist is at the highest point of the death - well, the normal reaction R on the motorcyclist by the ceiling of the chamber acts downwards. His weight mg also act downwards.

Fnet=mac⇒R+mg=rmv2

Here v is the speed of the motorcyclist and m is the mass of does not fall down. The minimum speed required to perform a vertical loop is given by equation (1) when R=0.

Therefore, 

mg=rmvmin2orvmin2=grorvmin=gr=9.8×25m/s=15.65m/s.

So, the minimum speed, at the top, required to perform a vertical loop is 15.65 m/s.

Answer 2

Concept:

To answer this question, we first recall the concept of speed of motion.

Speed of motion is referred as the rate of motion of an object i.e. the distance travelled by an object in unit time.

To find:

The safest Speed of motion of a cyclist in a death well

Solution:

When the cyclist in a death well  is at highest point , the normal reaction R by ceiling of chamber acts downwards and weight of cyclist  i.e. mg also acts downwards

Therefore, net force F = ma

                    i.e. R+mg = $\frac{mv^{2} }{r}$

v is the speed of cyclist and m is mass of not falling

Safest speed is when R=0

                                mg = $\frac{mv^{2} }{r}$

                                  gr = $v^{2}$

                               $\sqrt{gr}$ = v    

 g= 9.8 m/$s^{2}$ and r =25m

 so, v=15.65 m/s

Hence, the safest speed is 15.65 m/s.