A golf ball rolls up a hill toward a miniature-golf hole. Assume the direction toward the hole is positive.
If the golf ball starts with a speed of 2 m/s and slows at a constant rate of .5 m/s2, what is its velocity after 2 s?
-What is the golf ball’s velocity if the constant acceleration continues for 6 seconds?

Respuesta :

Answer:

a) 1m/s

b) -1m/s

Explanation:

So the ball starts rolling up the hill with a speed of 2m/s (v0=2m/s) and it decelerates at a constant rate of 0.5 m/s2 (a = -0.5 m/s², minus because it decelerates).

Now, the equation for calculating velocity is:

v = v0 + a • t, where t represents time

So, ball's velocity after 2 seconds is:

v = 2m/s + (-0.5m/s²• 2s)

v = 2m/s + (-1m/s)

v = 1m/s

We use the same formula for finding ball's velocity after 6 seconds:

v = v0 + a • t

v = 2m/s + (-0.5m/s² • 6s)

v = 2m/s + (-3m/s)

v = -1m/s

Of course, velocity can't be negative, this only means that the ball moves in 1m/s velocity, only in opposite direction (downhill).