Question

Motor neurons in mammals transmit signals from the brain to skeletal muscles at approximately 25 m/s. Estimate how long in ms it takes a signal to get from your brain to your hand.

Short answer

The time required for a signal to reach from the brain to the hand is$32ms$.

Step-by-step solution

Given information

The speed of signals from the brain to skeletal muscles is$v=25\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$.

Time required for a signal to reach from brain to hand.

Suppose the distance between your brain and your hand is $0.8m$.

The average speed is given by $v=\frac{∆x}{∆t}$.

Substitute the known values.

role="math" localid="1648567732955" $$\begin{gathered} 25\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.=\frac{0.8m}{∆t} \\ ∆t=0.032 \\ =32\times {10}^{-3}s \\ =32ms \end{gathered}$$

Therefore, the time required for a signal to reach from the brain to the hand is$32ms$.