Answer:
Given that
D= 4 mm
K = 160 W/m-K
h=h = 220 W/m²-K
ηf = 0.65
We know that

For circular fin


m = 37.08


By solving above equation we get
L= 36.18 mm
The effectiveness for circular fin given as


ε = 23.52
Answer:

Explanation:
We are asked to find the final velocity of the boat.
We are given the initial velocity, acceleration, and time. Therefore, we will use the following kinematic equation.

The initial velocity is 2.7 meters per second. The acceleration is 0.15 meters per second squared. The time is 12 seconds.
= 2.7 m/s - a= 0.15 m/s²
- t= 12 s
Substitute the values into the formula.

Multiply the numbers in parentheses.




Add.

The final velocity of the boat is <u>4.5 meters per second in the positive direction.</u>
Answer:
north direction.
Explanation:
The wire carries a current towards the east . The magnetic field will make circular path around the wire in clockwise direction so at a point just south of wire , magnetic field will be into the plane of paper containing wire. If we take east as x -axes , north as y axes then out of plane will form z axes. Hence direction of magnetic field will be - z direction .
Magnetic field can be represented as - B k
Proton is moving towards east ie in + x direction so it can be represented as follows
velocity = V i
Force F = q( V i x -B k)
= ( BqV) j or + ve j direction or along north direction
So direction of force will be along north direction.
Answer:
Collision theory is used to predict the rates of chemical reactions, particularly for gases. It is based on the assumption that for a reaction to occur for the reacting species (atoms or molecules) must come together or collide with one another. Not all collisions, however, bring about chemical change.
If two molecules collide with sufficient activation energy, there is no guarantee that the collision will be successful. In fact, the collision theory says that not every collision is successful, even if molecules are moving with enough energy. The reason for this is because molecules also need to collide with the right orientation so that the proper atoms line up with one another, and bonds can break and re-form necessarily.
Answer:
im pretty sure its D) ...