Answer:
From certain assumptions that the walking speed is 2 m/s, and the stop time is 0.1 s the acceleration would be -20 m/s
Explanation:
Using the average acceleration formula:
where 
and 
are the changes in the speed and time respectively.
We have by assuming that the walking speed is 2 m/s and the stop time is 0.1s which is equal to the change in time during the stopping.
, where 
are the initial speed and final speed respectively, and 
Plugging the previous in the average acceleration formula we get
where the minus sign indicates an acceleration in the opposite direction of the motion (or in other word opposite to the speed's direction).
Many of today’s mathematicians use computers to test cases that are either too time-consuming or involve too many variables to test manually, allowing the exploration of theoretical issues that were impossible to test a generation ago.
Answer: Option A
<u>Explanation:</u>
One of the most useful inventions in scientific world are the computers. We can use different programming language and create programs in them. These programs help other to solve difficult problems. Most of the theoretical problems in science can be solved by using these programming features in computer within a specific time limit.
Otherwise, earlier mathematician used to take months to solve a complex mathematical problem manually, but now with the inclusion of computers, the mathematician can solve the problems containing more number of variables or other theoretical issues.
Explanation:
A molecule can be made up from same or different elements. Whereas a compound will have different atoms.
Therefore, the difference between a molecule and a compound is that a compound is made up of atoms from different elements.
For example, 
is a molecule and NaCl is a compound.
And a chemical change creates a new substance.
Answer:
F = 294.3 [N]
Explanation:
To solve this problem we must use Newton's second law which tells us that force is equal to the product of mass by acceleration. It is this particular case the acceleration is due to the gravitational acceleration since the body is in free fall.
Therefore we have:
F = m*g
where:
F = force [N]
m = mass = 30 [kg]
g = gravity acceleration = 9.81 [m/s^2]
F = 30*9.81
F = 294.3 [N]
Answer:
O D.
Explanation:
Physics has an aspect that deals with the study of energy
