Step 1: Write the formula for work done.
The work done W by a force F along a curve C is given by the line integral:
W=∫CF⋅dr
The force is given as F=3x2i+(2x−y)j+zk.
The curve is parameterized by x=2t2, y=t, z=4t2−t, from t=0 to t=1.
Step 2: Express F in terms of t.
Substitute x=2t2, y=t, and z=4t2−t into the expression for F:
Fx=3x2=3(2t2)2=3(4t4)=12t4
Fy=2x−y=2(2t2)−t=4t2−t
Fz=z=4t2−t
So, F(t)=12t4i+(4t2−t)j+(4t2−t)k.
Step 3: Find dr in terms of t.
The position vector is r(t)=x(t)i+y(t)j+z(t)k.
r(t)=2t2i+tj+(4t2−t)k
Now, find the differential dr=dtdrdt:
dtdx=dtd(2t2)=4t
dtdy=dtd(t)=1
dtdz=dtd(4t2−t)=8t−1
So, dr=(4ti+1j+(8t−1)k)dt.
Step 4: Calculate the dot product F⋅dr.
F⋅dr=(Fxdtdx+Fydtdy+Fzdtdz)dt
F⋅dr=((12t4)(4t)+(4t2−t)(1)+(4t2−t)(8t−1))dt
F⋅dr=(48t5+4t2−t+(32t3−4t2−8t2+t))dt
F⋅dr=(48t5+4t2−t+32t3−12t2+t)dt
Combine like terms:
F⋅dr=(48t5+32t3+(4t2−12t2)+(−t+t))dt
F⋅dr=(48t5+32t3−8t2)dt
Step 5: Integrate from t=0 to t=1.
W=∫01(48t5+32t3−8t2)dt
W=[648t6+432t4−38t3]01
W=[8t6+8t4−38t3]01
Step 6: Evaluate the definite integral.
W=(8(1)6+8(1)4−38(1)3)−(8(0)6+8(0)4−38(0)3)
W=(8+8−38)−(0)
W=16−38
To subtract, find a common denominator:
W=316×3−38
W=348−38
W=340
The work done is 340.