1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VMariaS [17]
3 years ago
9

Given a = 2i+j – 2k b= -1 – 7j+k Find a x b

Mathematics
1 answer:
castortr0y [4]3 years ago
7 0

Step-by-step explanation:

a = 2i + j - k

b = -1 -7j + k

a × b = (2i + j - k) (-1 + 7j + k)

-2i + 14ij + 2ik - j + 7j^2 + jk + k -7jk - k^2

-2i + 14ij + 2ik -j +7j^2 +jk - 7jk + k - k^2

-2i + 14ij + 2ik - j +7j^2 - 6jk + k - k^2

You might be interested in
Can someone please help me with this?!
blagie [28]
The answer is 48 because 8 times 9
8 0
3 years ago
NASA launches a rocket at t=0 seconds. Its height, in meters above sea-level, as a function of time is given by h(t)=−4.9t2+121t
Alenkasestr [34]

NASA launches a rocket at t = 0 seconds. Its height, in meters above sea-level, as a function of time is given by

h(t)=-4.9t^2+121t+283

The sea level is represented by h = 0, therefore, to find the corresponding time when h splashes into the ocean we have to solve for t the following equation:

h(t)=0\implies-4.9t^2+121t+283=0

Using the quadratic formula, the solution for our problem is

\begin{gathered} t=\frac{-(121)\pm\sqrt{(121)^2-4(-4.9)(283)}}{2(-4.9)} \\ =\frac{121\pm142.083778...}{9.8} \\ =\frac{121+142.083778...}{9.8} \\ =26.8452834694... \end{gathered}

The rocket splashes after 26.845 seconds.

The maximum of this function happens at the root of the derivative. Differentiating our function, we have

h^{\prime}(t)=-9.8t+121

The root is

-9.8t+121=0\implies t=\frac{121}{9.8}=12.347

Then, the maximum height is

h(12.347)=1029.99

1029.99 meters above sea level.

6 0
1 year ago
10-kg batch of a food product has a moisture content of175% dry basis. Calculate the amount of water to beremoved from the produ
sleet_krkn [62]

Answer:

4.9kg of water

Step-by-step explanation:

Dry basis is the percentage ratio of moisture amount to amount of dry product which is 175%

Ratio of moisture amount to dry product = 175 : 100

Mass of food product = 10kg

Amount of moisture in food product = 175/175+100 × 10kg = 175/275 × 10kg = 6.4kg

Wet basis is the percentage ratio of the moisture amount to the total weight of material which is 15%

Ratio of moisture amount to total weight of material is 15 : 100

Amount of moisture in food product = 15/100 × 10kg = 1.5kg

Amount of water contained in the final product = 1.5kg

Amount of other components in the food product = 10kg - 6.4kg = 3.6kg

Total amount = 1.5kg + 3.6kg = 5.1kg

% of water = 1.5kg/5.1kg × 100 = 29%

3 0
3 years ago
Megan slept for 7.5 hours. What is this in hours and minutes?
exis [7]

Answer:

7 hours and 50 minutes

7.5 is equal to 7 hours and 50 minutes

7 0
3 years ago
Read 2 more answers
There are 24 pictures on a roll of film. Adelle had 84 pictures from her trip home. She said that 12 other pictures were spoiled
galina1969 [7]
The answer is 4.

There were in total 96 pictures (84 pictures  + 12 spoiled = 96 pictures).
1 roll of film has 24 pictures. x rolls of film have 96 pictures.
1 : 24 = x : 96
x = 1 * 96 : 24
x = 4


6 0
3 years ago
Other questions:
  • Erin loves to play sports! She has earned 333 tennis trophies, 444 basketball trophies, 777 soccer trophies, and 111 volleyball
    15·2 answers
  • Find an equation for the line that passes through the point (2, −9) and is parallel to the y-axis.
    13·1 answer
  • Will vote Brainliest! Find the quotient of the image below. Answer choices are:
    7·2 answers
  • What is 2/5 - 1/6 as a fraction ​
    12·1 answer
  • 3/4 Multiply 2/7 simplest form
    10·2 answers
  • The density function for the number of times the riders scream on a roller coaster is given by....
    15·1 answer
  • Which strategy would you use to find 2+8 ? explain how you decided.
    9·2 answers
  • Please help me answer these. I am not good at graphs and this is overdue and i need this done. Will mark brainliest.
    11·1 answer
  • My exam, does any one know the answer
    7·2 answers
  • The sequence consisting of all natural numbers from 25 to 999 is given as follows.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!