Answer:
a = 6.4 [m/s²]
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration. In this way, we have the following equation.
∑F = m*a
where:
∑F = sum of forces (horizontal force = 40 [N] and friction force = 8 [N])
m = mass of the block = 5 [kg]
a = acceleration [m/s²]
Now replacing:
![40-8=5*a\\32 = 5*a\\a=6.4[m/s^{2} ]](https://tex.z-dn.net/?f=40-8%3D5%2Aa%5C%5C32%20%3D%205%2Aa%5C%5Ca%3D6.4%5Bm%2Fs%5E%7B2%7D%20%5D)
Note: the sign of the friction force is negative since this force is acting against the movement of the block.
I think it's C, longer wave length.
The answer is so that everyone is measuring the same distance and counting that distance as the same everywhere. one example from real life why it is important to use standard units is the loss of the NASA mars orbiter. some people decided that the units were to be in metric and others thought that the units were in imperial (english) system. so the orbiter was lost.
let's eliminate some choices
A. to allow for consistientcy with measurement data:
not really, just make sure the instruments are accurate.
B. to use tools marked in customary units: this could be true because a custom is something that is accepted in a wide area and if it is standard, then it is customary so b is the answer
C. so they can keep measurement data secret: nope
D. to record with easier abbreviations: not really
the answer is B
Depends on the elasticity and density of the medium through what it is traveling <span> </span>
Answer:
moving the boxes and the furniture up to the fifth floor.
Explanation:
The work done when moving an object up or down is equal to its change of gravitational potential energy:
where
m is the mass of the object
g is the gravitational acceleration
is the change in height of the object
We have two opposite situations:
1) when an object is moved upward, is positive, so the work done W is positive as well: this means that we need to do work in order to move the object, because we have to "win" the effect of gravity, which pulls the object downward
2) when an object is moved downward, is negative, so the work done W is negative as well: this means that we do not need to do work on the object, because it is already done by gravity, which pulls the object downward.
Therefore, more work is done when we are moving the boxes and the furniture up to the fifth floor.
