Question

the horizontal velocity to be given to Bob of a simple pendulum length 400cm so that it makes just one revolution​

Answer 1

Given :-

Length of the string of pendulum = 400 cm

To Find :-

The minimum velocity for the Bob to complete just one revolution.

Analysis :-

Here we are given with the length of the string of the pendulum.

In order to find the minimum velocity for the bob to complete just one revolution; substitute the values accordingly such that velocity is equal to root 5 into gravity into radius.

Solution :-

We know that,

• g = Gravity
• v = Velocity
• r = Radius

Using the formula,

$\underline{\boxed{\sf Velocity= \sqrt{5 \times Gravity \times Radius} }}$

Given that,

Gravity (g) = 10 m/s

Radius (r) = 400 cm

= 1 cm = 0.01 m

= 400/100

= 4 m

Substituting their values,

⇒ v = √5 × 10 × 4

⇒ v = √200

⇒ v = 14.14 m/s

Therefore, the minimum velocity for the Bob to complete just one revolution is 14.13 m/s.

Answer 2

Answer :-

➪ Horizontal velocity $\leadsto$ $\boxed{\tt{\red{25.14\:m/s}}}$

Given :-

• Length (or) radius = 400 cm = 4m

• Angular velocity ($\omega$) = 2$\pi$

To find :-

• Horizontal velocity

Formula used :-

• $\boxed{\sf{v = r \omega}}$

Solution :-

$\sf{➪\:v = r \omega}$

By substituting values,

$\sf{➪\:v = 4\times 2\pi}$

$\sf{➪\:v = }$$\bold{\red{25.14\:m/s}}$