Answer:
<u><em>1) if they are moving away from each other it will take 1.43 secs</em></u>
<u><em>2) if they are moving towards each other then it will take 1.11 secs</em></u>
Explanation:
Distance between them is 10 m
Speed ( if they are moving towards each other)= distance/time
time = 10/8+1
time = distance / speed= 10/9= 1.11 secs
if they are moving away from each other than it will take
time = 10/8-1= 10/7= 1.43 secs
Answer:

Explanation:
As we know that the force equation at the top is given as

now we know that

so we have


so we will have


Answer:
a) W = 6.75 J and b) v = 3.87 m / s
Explanation:
a) In the problem the force is nonlinear and they ask us for work, so we must use it's definition
W = ∫ F. dx
Bold indicates vectors. In a spring the force is applied in the direction of movement, whereby the scalar product is reduced to the ordinary product
W = ∫ F dx
We replace and integrate
W = ∫ (-60 x - 18 x²) dx
W = -60 x²/2 -18 x³/3
Let's evaluate between the integration limits, lower W = 0 for x = -0.50 m, to the upper limit W = W for x = 0 m
W = -30 [0- (-0.50) 2] -6 [0 - (- 0.50) 3]
W = 7.5 - 0.75
W = 6.75 J
b) Work is equal to the variation of kinetic energy
W = ΔK
W = ΔK = ½ m v² -0
v =√ 2W/m
v = √(2 6.75/ 0.90)
v = 3.87 m / s
Answer:
The answer is the 1st one