Answer:
The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.
Explanation:
Answer:
He's 3 miles west of school.
Explanation:
He went 5 miles up and 5 miles down which means that he really didn't go up or down. In between that, he went 3 miles west so if the 5 milers don't count, this puts him at 3 miles west of school.
Answer:
588 J
Explanation:
PE (potential energy) = (mass) x (gravity) x (height)
mass = 12 kg
gravity = 9.8m/s^2
height = 5 m
PE = (12) x (9.8) x (5) = 588 J (Joules)
Answer:
The correct answer is:
(a) 84.240 kg
(b) 24.038 m
Explanation:
The given values are:
Force,
F = 81.0 N
Distance,
S = 13.0 m
Time,
t = 5.20 s
As we know,
The acceleration of mass will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
⇒ 
(a)
The mass of the block will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
(b)
The final velocity after a given time i.e.,
t = 5.00 s
⇒ 
On substituting the values, we get
⇒ 
⇒ 
In time, t = 5.00 s
The distance moved by the block will be:
⇒ 
On putting the values, we get
⇒ 
⇒ 
Answer:
it is safe to stand at the end of the table
Explanation:
For this exercise we use the rotational equilibrium condition
Στ = 0
W x₁ - w x₂ - w_table x₃ = 0
M x₁ - m x₂ - m_table x₃ = 0
where the mass of the large rock is M = 380 kg and its distance to the pivot point x₁ = 850 cm = 0.85m
the mass of the man is 62 kg and the distance
x₂ = 4.5 - 0.85
x₂ = 3.65 m
the mass of the table (m_table = 22 kg) is at its geometric center
x_{cm} = L/2 = 2.25 m
x₃ = 2.25 -0.85
x₃ = 1.4 m
let's look for the maximum mass of man
m_{maximum} =
let's calculate
m_{maximum} =
(380 0.85 - 22 1.4) / 3.65
m_{maximum} = 80 kg
we can see that the maximum mass that the board supports without turning is greater than the mass of man
m_{maximum}> m
consequently it is safe to stand at the end of the table