Acid it is i believe........
Answer:

Explanation:
= Cambio en la longitud de la cuerda = 0.25 cm
T = tensión en cuerda
A = Área de la cadena = 
d = Diámetro de la cuerda = 0.2 cm
L = Longitud original de la cuerda = 1.6 m
El cambio de longitud de una cuerda viene dado por

La tensión en la cuerda es
.
Answer:
Negative 9.8 meters per second squared
Explanation:
The negative is for the direction (down, towards the center of the earth). Often this can be estimated as -10 m/s^2 to make calculations easier.
Here we deal with a lever law. It states that product of force and distance from a fixed point on a lever is equal on both sides.
F₁*d₁ = F₂*d₂
By analysing this formula we can see that applying small force on a great length equals great force on a small length.
To remove nail we need to apply certain force. If we use F₁ for this required force we can see that on other side we need to apply certain force. If we have greater arm length we need smaller force. In a crowbar arm length along which we apply force is greater than length of our arm. This leads to a conclusion that we need smaller force when using crowbar. Depending on the length of a nail it is possible that we need to apply force that is greater than force required to remove nail.
Answer:
<u>velocity of swimmer relative to ground = 3 i -5 j</u>
Explanation:
- To cross a river the swimmer swims relative to river in perpendicular direction.
Velocity of river = -5 j (south)
Velocity of swimmer relative to river = 3 i(north)
So
<h2>
Velocity of swimmer relative to ground = Velocity of swimmer relative to river + Velocity of river</h2>
Velocity of swimmer relative to ground = 3 i -5 j
So magnitude of total velocity is
=
= 