In the amusement park ride known as Magic Mountain Superman, powerful magnets accelerate a car and its riders from rest to 45 m/s (about 100 mi/h) in a time of 7.0 s. The combined mass of the car and riders is 5.5 × 103 kg. Find the average net force exerted on the car and riders by the magnets.

I've got an estimated answer of 35357.135N but I have doubts about this answer. Am I correct?

Let me show my process:

v= 45 m/s
vo= 0 m/s
t= 7.0 s
m = 5.5 x 10^3 kg
a=?
F=?

To solve for acceleration, I've used a kinematics equation:

v=vo+at

a= (45 m/s) / (7.0 s) = 6.428 m/s^2

Then we use Newton's 2nd law:

F=ma
F= (5.5 x 10^3 kg)(6.428 m/s^2)
F is estimated to be 35354 N

force=mass*acc=5.5e4*45/5=not your answer.

How am I incorrect though? I've used a kinematics equation v=vo+at, which resulted in me getting my acceleration and plugged in Newton's 2nd law as well as multiplying the acceleration by the given mass, resulting in an answer similar to this, only I believe that I may have made a round-off error on one of the two attempts.

your answer is better than mine, I read the mass as 5.5e4, not 5.5e3 as stated. Misread. Significant figures should be 2 places.

To find the average net force exerted on the car and riders by the magnets, we can use Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the acceleration can be calculated using the formula a = (v - u) / t, where v is the final velocity, u is the initial velocity, and t is the time.

Given:
Mass of the car and riders (m) = 5.5 × 10^3 kg
Initial velocity (u) = 0 m/s (since they start from rest)
Final velocity (v) = 45 m/s
Time (t) = 7.0 s

First, let's calculate the acceleration:
a = (v - u) / t
= (45 - 0) / 7.0
= 45 / 7.0
≈ 6.43 m/s^2

Now, we can calculate the average net force:
F = m * a
= 5.5 × 10^3 kg * 6.43 m/s^2
≈ 35315 N

Based on the significant figures provided, your estimated answer of 35357.135 N is quite close to the calculated value of 35315 N. However, since the given values in the question are rounded, it's best to round our final answer to the correct number of significant figures. In this case, the answer will be 35300 N.

also , be aware of SIGNIFICANT FIGURES