Answer:
40 N
Explanation:
We first need to calculate the acceleration of the tron ball.
Since acceleration, a = (v - u)/t where u = initial velocity of iron ball = 17m/s, v = final velocity of iron ball = 27m/s and t = time taken for the change in velocity = 5 s.
So, a = (v - u)/t
= (27 m/s - 17 m/s)/5 s
= 10 m/s ÷ 5 s
= 2 m/s²
We know force on iron ball, F = ma where m = mass of iron ball = 20 kg and a = acceleration = 2 m/s²
So, F = ma
= 20 kg × 2 m/s²
= 40 kgm/s²
= 40 N
So, the magnitude of the force on the iron ball is 40 N.
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
MgCl2 is Magnesium chloride
Answer:
the elastic potencial energy stored when the spring is compressed x=8 cm is K(x)= 0.048 J
Explanation:
since the work is related with the force through
W=∫F dx
for a spring of constant k :
F=k*x , where F= compression force, x= compression length
then for a compression from 0 until x
W=∫F dx = ∫ k*x dx = k ∫x dx =1/2*k*x² - 1/2*k*0² = V(x) - V(0)
since the work depends only on the final value of compression and not on the process 1/2*k*x² represents the elastic potential energy V stored in the spring, then
V(0) = 1/2*k*0² = 0
V(x) = 1/2*k*x²
when the spring is compressed x= 8 cm = 0.08m , the elastic potencial energy is
V (x) = 1/2*k*x² = 1/2 * 15 N/m* (0.08m)² = 0.048 J
