Question

An object starts at position -2m with an initial velocity of -4 m/s and a constant acceleration of +3 m/s^2.

a. In which direction is the object traveling initially?
b. What will be the object's velocity after 1s, 2s, 3s?
c. What will the objects position be after 3s?

Answer 1

here is the answer

Step-by-step explanation:

a) since displacement is given as a negative value, object must travelling i the negative direction (with respect to a cartesian plane).

b) after 1 second

v = u + at

v = -4 + 3× 1

v = -4 + 3

v = -1 m/s

after 2 seconds

v = -4 + 3×2

v = -4 + 6

v = 2 m/s

after 3 seconds

v = -4 + 3×3

v = -4 + 9

v = 5 m/s

c) we need to find the position after three seconds

initial velocity= u= -4m/s

final velocity = v= 5 m/s ( as previously calculated)

acceleration=3m/s²

s = ut + 1/2 × at²

s = -4×3 + 1/2 × 3×(3)²

s = -12 + 1/2 × 27

s = -12 + 27/2

s = 1.5 meters ( in the positive direction; as time has increased and acceleration in positive)

position = -2 + 1.5 = -0.5 meters

(s indicates distance travelled)