In which object or place is convection most likely to transfer heat?

Given that two vectors A = 5i-7j-3k, B = -4i+4j-8k find A×B

WARRIOR [948]

$\textbf{A}×\textbf{B}= 68\hat{\textbf{i}} + 52\hat{\textbf{j}} - 8\hat{\textbf{k}}$

Explanation:

Given:

$\textbf{A} = 5\hat{\textbf{i}} - 7\hat{\textbf{j}} - 3\hat{\textbf{k}}$

$\textbf{B} = -4\hat{\textbf{i}} + 4\hat{\textbf{j}} - 8\hat{\textbf{k}}$

The cross product $\textbf{A}×\textbf{B}$ is given by

$\textbf{A}×\textbf{B} = \left|\begin{array}{ccc}\hat{\textbf{i}} & \hat{\textbf{j}} & \hat{\textbf{k}} \\\:\:5 & -7 & -3 \\ -4 & \:\:4 & -8 \\ \end{array}\right|$

$= \left|\begin{array}{cc}-7 & -3\\\:4 & -8\\ \end{array}\right|\:\hat{\textbf{i}}\:+\:\left|\begin{array}{cc}-3 & \:\:5\\-8 & -4\\ \end{array}\right|\:\hat{\textbf{j}}\:+\: \left|\begin{array}{cc}\:\:5 & -7\\-4 & \:\:4\\ \end{array}\right|\:\hat{\textbf{k}}$

$= 68\hat{\textbf{i}} + 52\hat{\textbf{j}} - 8\hat{\textbf{k}}$

5 0

3 years ago

Debby and Ben took different routes to travel from Point A to Point E. Debby took the route along A, B, C, D, and E. Ben took th

svetlana [45]

Answer:

Ben's average speed was twice Debby's average speed.

Explanation:

Ben covered a total distance of 16 miles (10+4+2) and Debby covered 8 miles (3+2+2+1) which is half of what Ben covered. As they both reached the place in the same amount of time it tells us Ben was faster.

4 0

4 years ago

Read 2 more answers

You are driving a metric car that has a speedometer that displays in meters per second. When you look down at your speedometer,

shepuryov [24]

Ahahhabsba babababba ab

7 0

3 years ago

A weightlifter deadlifts a 300 kg weight. If the weightlifter has a mass of 100 kg, what is the force acting on his legs?

sergeinik [125]

300 + 100 = 400

(Im not 100% sure of this answer)

3 0

3 years ago

Read 2 more answers

Cross product and its properties

bearhunter [10]

The length of the cross product of two vectors

The scalar triple product of the vectors a, b, and c

The volume of the parallelepiped determined by the vectors a, b, and c is the magnitude of their scalar triple product.

<u>Explanation</u>:

The length of the cross product of two vectors is | a $\times$ b | = |a| |b| sin θ

The length of the cross product of two vectors is equal to the area of the parallelogram determined by the two vectors (see figure below).

Anticommutativity:

| a $\times$ b | = - | b $\times$ a |

Multiplication by scalars:

(ca) $\times$ b = c (a $\times$ b) = a $\times$ (cb)

Distributivity:

a $\times$ (b + c) = (a $\times$ b) + (a $\times$ c)

The scalar triple product of the vectors a, b, and c:

a . (b $\times$ c) = (a $\times$ b) . c

The magnitude of the scalar triple product is the volume of the parallelepiped of the vectors a, b, and c.

The vector triple product of the vectors a, b, and c is given as

a $\times$ (b $\times$ c) = (a.c) b - (a.b) $\times$ c

4 0

4 years ago