Question

Please help me i don't get it

Answer 1

Answer:

39)

a) distance traveled = 1 mile

b) displacement = 0 mile

40)  - 4 (m/s)

41-) distance traveled = 5 [m]

displacement = 3.6 [m]

Explanation:

The distance differs from the displacement, the distance traveled is equal to the sum of all displacements made by the particle or object.

Displacement is the difference between the initial point and the final point where the object or particle was stopped.

Then we can use the equation given:

$a=\frac{(v_{f} - v_{i} )}{t} \\where:\\v_{f}=16[m/s]\\v_{i}=2[m/s]\\t=3.5[s]\\a=\frac{(2-16)}{3.5}\\ a=-4[m/s]$

The minus sign means the particle is slowing down.

For the 41) we can see the attached image.

In the graph we can see that the particle moves north 3 miles, so that the first distance is 3 miles, then moves 2 miles east being the second distance of 2 miles. Thus the sum of the distances is 3 + 2 = 5 miles.

Displacement is the difference between the endpoint and the initial point since the form of displacement is a straight line, we can use the formula of the straight line or the theorem of Pythagoras.

$d=\sqrt{(2-0)^{2}+(3-0)^{2} }\\d=3.6 [mi]$