Sorry, I don't know but I think the correct answer is the first option.
Answer:
The free body diagram is attached.
Explanation:
A force of 31[N] to the east, the second force goes to the south and it is equal to 28[N], the third force goes to the west and it is equal to 39 [N].
We can consider the crate as a particle. And all the forces are acting over the particle.
Explanation:
KE = 1/2*m*v^2
mass won't change
but velocity is
A: the force is pushing against the direction of the object, so velocity is decreasing, so KE is decreasing
B: the F net line is pretty much straight up, which means there is no net force pushing to the left, but velocity is still increasing
Why? Because if you use the pythagorean theorem, the hypotenuse is always longer than the legs.
Note: velocity only ever stays the same if there is no net force (or 0 acceleration), so all four of these are either decreasing or increasing
C: there is a net force to the right, so velocity is increasing
D: There is a net force to the right but velocity is to the left, so velocity is decreasing
Hope I got these right
Answer:
t = 25.5 min
Explanation:
To know how many minutes does Richard save, you first calculate the time that Richard takes with both velocities v1 = 65mph and v2 = 80mph.

Next, you calculate the difference between both times t1 and t2:

This is the time that Richard saves when he drives with a speed of 80mph. Finally, you convert the result to minutes:

hence, Richard saves 25.5 min (25 min and 30 s) when he drives with a speed of 80mph