Here are the solutions to questions 1 and 2.
Question 1 (b):
Evaluate ∫12(3x3+2x2−x+1)dx.
Step 1: Find the indefinite integral of the function.
∫(3x3+2x2−x+1)dx=3+13x3+1+2+12x2+1−1+1x1+1+x+C
=43x4+32x3−21x2+x+C
Step 2: Evaluate the definite integral using the Fundamental Theorem of Calculus, F(b)−F(a).
[43x4+32x3−21x2+x]12
First, evaluate at the upper limit x=2:
F(2)=43(2)4+32(2)3−21(2)2+2
F(2)=43(16)+32(8)−21(4)+2
F(2)=12+316−2+2
F(2)=12+316=336+316=352
Next, evaluate at the lower limit x=1:
F(1)=43(1)4+32(1)3−21(1)2+1
F(1)=43+32−21+1
Find a common denominator, which is 12:
F(1)=129+128−126+1212
F(1)=129+8−6+12=1223
Step 3: Subtract F(1) from F(2).
∫12(3x3+2x2−x+1)dx=F(2)−F(1)=352−1223
=3×452×4−1223=12208−1223
=12208−23=12185
The final answer is 12185.
Question 2 (5):
A car with a mass of 1600kg starts from rest and accelerates to a speed of 18m/s in 10seconds. The frictional force is 500N.
i. calculate the force required to accelerate the car
Step 1: Identify the given values and calculate the acceleration.
Given:
Mass (m) = 1600kg
Initial velocity (u) = 0m/s (starts from rest)
Final velocity (v) = 18m/s
Time (t) = 10s
Frictional force (Ff) = 500N
Using the kinematic equation v=u+at:
18m/s=0m/s+a×10s
18=10a
a=1018m/s2=1.8m/s2
Step 2: Calculate the net force (Fnet) required for acceleration using Newton's second law (Fnet=ma).
Fnet=1600kg×1.8m/s2
Fnet=2880N
Step 3: Calculate the total applied force (Fapplied) needed to overcome friction and cause acceleration.
The net force is the applied force minus the frictional force (Fnet=Fapplied−Ff).
Fapplied=Fnet+Ff
Fapplied=2880N+500N
Fapplied=3380N
The force required to accelerate the car is 3380N.
ii. find the distance traveled within the time.
Step 1: Use a kinematic equation to find the distance (s).
Using the equation s=ut+21at2:
s=(0m/s)(10s)+21(1.8m/s2)(10s)2
s=0+21(1.8)(100)
s=0.9×100
s=90m
The distance traveled is 90m.
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