Answer:
AFter 3.5 s, the wagon is moving at: 
Explanation:
Let's start by finding first the net force on the wagon, and from there the wagon's acceleration (using Newton's 2nd Law):
Net force = 250 N + 178 N = 428 N
Therefore, the acceleration from Newton's 2nd Law is:

So now we apply this acceleration to the kinematic expression for velocity in an object moving under constant acceleration:

School Planners Designed To Your Exact Requirements. Create Student And Teacher Planners That Are 100% Relevant To Your School. Request Info. Pack Today.
Answer:
12 Neutrons
Explanation:
So the mass of sodium is 22.990. You round it up to get 23(as stated in the problem). So, <em>what exactly is atomic mass?</em>
Atomic Mass is the total amount of neutrons and protons added up to form a total mass. So when you subtract 23-11 you get 12 Neutrons.
<u>Tip: </u>Don't know if you need this but-
The neutrons and protons are typically close in number (unless it's an isotope). So say that you subtract and the numbers of protons and neutrons aren't close at all. Well if that's the case, it's probably wrong.
hope this helps!!
Answer:
momentum=mass x velocity= 10 x 2 = 20kgm/s
Looking at the force-time graph, wouldn't the force be integral fdt between 0 and 10s, a sort of "smoothed out pulse" ? And it looks like a familiar bell shaped curve. doesn't that produce a turning effect/torque and isn't there something about a circular analogue to F=ma in newtonian linear mechs ???
Looks like a difficult question for 5 points