(a) Given the position function
x(t) = (B m/s²) t² + 5 m
it's clear that the object accelerates at B m/s² (differentiate x(t) twice with respect to t), so that the force exerted on the object is
F(t) = (2 kg) (B m/s²) = 2B N
(b) Recall the work-energy theorem: the total work performed on an object is equal to the change in the object's kinetic energy. The object is displaced by
∆x = x(5 s) - x(0 s)
∆x = ((B m/s²) (5 s)² + 5 m) - ((B m/s²) (0 s)² + 5 m)
∆x = 25B m
Then the work W performed by F (provided there are no other forces acting in the direction of the object's motion) is
W = (2B N) (25B m) = 50B² J = 200 J
Solve for B :
50B² = 200
B² = 4
B = ± √4 = ± 2
Since the change in kinetic energy and hence work performed by F is positive, the sign of B must also be positive, so B = 2 and the object accelerates at 2 m/s².
(c) We found in part (b) that the object is displaced 25B m, and with B = 2 that comes out to ∆x = 50 m.
Answer:
9 ft
Step-by-step explanation:
So let's assume the shape is rectangular.
The perimeter of the rectangle with dimensions l and w is: 2w+2l.
We are given 48 feet of wood so we want 2w+2l=48.
Manny wants l to be 15 so insert this into equation: 2w+2(15)=48.
Now we need to solve
2w+2(15)=48
Multiplying 2 and 15:
2w+30=48
Subtract 30 on both sides:
2w =18
Divide both sides by 2:
w =9
We want the width to be 9 ft.
Answer:
fgggg
Step-by-step explanation:
Answer:
x=6,-6
Step-by-step explanation:
and 36
(x+6)(x-6)=0\\
x=6,-6[/tex]\\