The speed of propagation of the action potential (an electrical signal) in a nerve cell depends (inversely) on the diameter of the axon (nerve fiber). If the nerve cell connecting the spinal cord to your feet is 1.3 m long, and the nerve impulse speed is 33 m/s, how long (in s) does it take for the nerve signal to travel this distance?

Explanation:

Speed of electrical nerve signal = 33 m /s

Distance travelled = 1.3 m

time taken = distance / speed

= 1.3 / 33  

= .039 s

= 39 ms ( millisecond )  .

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards

no. bullets are macro objects. wave nature is for light waves, extremely tiny particles. if a light particle was the size of your finger, the bullet would be the size of the universe. so basically, that huge difference in size makes the wave nature of matter insignificant.