Answer:
Δy = 7.1 cm
Explanation:
The center of mass of a body is defined
= 1 /M ∑
i
Where M is the total mass of the body, m mass of each part and ‘y’ height
Let's apply this equation to our case
We locate the reference system on the shoulders
The height of the arms is at its midpoint
y = -75/2 = 37.5 cm
With arms down
= 1/70 (63 y₀ - 3.5 37.5 - 3.5 37.5)
= 1/70 (63 y)₀ - 7 37.5)
With arms up
’= 1/70 (63 y₀ + 3.5 y + 3.5 y)
’= 1/70 (63y₀ + 7 35.5)
let's subtract the two equations
’ - = 1/70 2 (7 35.5)
Δy = ’ - = 2 7 35.5 / 70
ΔY = 7.1 cm
Mass will remain unchanged, always. His weight, which is the gravitational force acting on that mass will be less in this case.
Substract two consecutive terms of the sequence to see if there is a common difference:
As we can see, there is a common difference of -6.
Then, if a number of the sequence is given, the next one can be found by adding -6 (which is the same as subtracting 6).
Notice that the first term of the sequence is 3.
Then, the rule for the sequence is to start with 3 and add -6 repeatedly.
Therefore, the correct choice is option A) Start with 3 and add -6 repeatedly.
The work done by the elephant to lift one log is the force multiplied by the height at which the log has been lifted:
And so, the total work done to lift the 7 logs is 7 times the work done to lift each log:
Answer:
Surely Achilles will catch the Tortoise, in 400 seconds
Explanation:
The problem itself reduces the interval of time many times, almost reaching zero. However, if we assume the interval constant, then it is clear that in two hours Achilles already has surpassed the Tortoise (20 miles while the Tortoise only 3).
To calculate the time, we use kinematic expression for constant speed:
The moment that Achilles catch the tortoise is found by setting the same final position for both (and same time as well, since both start at the same time):
