What do you mean by plank?

Definition of plank (Entry 1 of 2) 1a : a heavy thick board especially : one 2 to 4 inches (5 to 10 centimeters) thick and at least 8 inches (20 centimeters) wide. b : an object made of a plank or planking. c : planking.

Is plank an exercise?

The plank exercise is an isometric core exercise that involves maintaining a position similar to a push-up for the maximum possible time.

What is the meaning of wooden plank?

A plank is timber that is flat, elongated, and rectangular with parallel faces that are higher and longer than wide. Used primarily in carpentry, planks are critical in the construction of ships, houses, bridges, and many other structures. Planks also serve as supports to form shelves and tables.

Can planks increase height?

Good posture increases your height, making you appear lean and actually increasing your height a bit; these bonuses come without an increase to weight (though this may naturally come as you continue working out.)

How are timber planks made?

The most common method of sawing coniferous softwood is block-sawing, followed by resawing. With block-sawing, the log is rotated to the best position and sawn through to make optimum use of the log’s dimensions. It is then laid down so the centrecut can be sawn into boards and planks.

How many planks does it take to stop a bullet?

A bullet looses (1/n)th of its velocity passing through one plank. The number of such planks that are required to stop the bullet can be? Logically, to me the answer seems to be infinity, as always a fraction of velocity will get reduced. But in my book the answer is n^2/ (2n-1) (that comes from energy balance).

What is the loss of velocity after penetrating 20 planks?

If we assume that the 1/20 (5\%) loss of velocity is a constant dependent on the original velocity of the bullet. Then the bullet would loose 5\% of its velocity after penetrating each plank. After 20 planks its velocity would be 0.

How much energy does it take to hit a second plank?

Assuming a simplified bullet model the energy of the bullet is based on kinetic energy E= 1/2 *mass* velocity^2. So the velocity of the bullet drops to a square of the energy drop. So the second plank will be hit at 81\% of the original speed.

What is the loss of velocity of a bullet after first plat?

The after the first plat it would retain 95\% of its velocity, after the second it would retai If this problem is seen as a logic or purely mathematical problem, then then answer is either 20 or infinite. If we assume that the 1/20 (5\%) loss of velocity is a constant dependent on the original velocity of the bullet.