Question

1. A hunting lion may cover 10 km in the span of 2.5 hours while searching for prey. Determine the lion’s average speed during this hunt.
2. A penny falls from the top of the Space Needle. It hits the ground 6 seconds later. How fast is the penny moving when it hits the ground?
3. Consider the same penny from #2, which hits the ground after 6 seconds. How far did the penny fall from the top of the Space Needle to the ground (this will give you the height of the Space Needle!)
4. As a train pulls out of the station, it reaches a speed of 60 km/h after 15 s. What was the train’s acceleration during this time?
5. A racecar might accelerate at 8 km/h/s at the start of a race. How far would racecar travel if it accelerates at this rate, from rest, for 9 seconds?
6. In March of 2018, Mr. Traynor ran a race in Atlanta. If he ran at an average speed of about 6.5 mph and ran for 4 hours, how long was the race?

Answer 1

Answer:

1)speed = total distance / total time

10/2.5= ?

Answer 2

Answer:

1. 4 km/hr

2. 58.9 m/s

3. 176.6 m

4. 1.11 m/s/s

5. 90 m

6. 26 miles

Explanation:

1. Given:

s = distance = 10 km

t = time = 2.5 hr

Let the average speed is v.

Average speed = distance / time

v = s/t

  = 10/2.5 km/hr

  = 4 km/hr [answer]

2. Given:

t = time = 6 s

a = g = 9.81 m/s/s

u = initial speed = 0

Let the speed when it hits the ground is v.

Using the kinematic equation:

v = u + at

  = 0 + gt

  = 9.81 x 6 m/s

  = 58.86 m/s

  = 58.9 m/s [answer]

3. Let the height is h.

using the kinematic equation:

$h=ut+\frac{1}{2}at^2\\ = 0 + \frac{1}{2}gt^2\\=\frac{1}{2}\times 9.81 \times 6^2 m\\= 176.58 m\\= 176.6 m [Answer]$

4. Given:

u = initial speed = 0 km/h

t = time 15 s

v = final speed = 60 km/h

Let the acceleration is "a".

Using the kinematic equation:

v = u + at

a = (v-u)/t

  $=\frac{60\times \frac{5}{18}-0}{15}\\= 1.11 m/s^2$   [answer]

5. Given:

a = acceleration = 8 km/h/s

t = time = 9 s

u = initial speed = 0

Let the distance traveled is s.

using the kinematic equation:

$s=ut+\frac{1}{2}at^2\\= 0 + \frac{1}{2}\times 8 \times \frac{5}{18}\times 9^2 m\\= 90 m$  [answer]

6. Given:

v = speed = 6.5 mph

t = time 4 hours

Let the distance traveled is s.

Using the equation:

s = vt

  = 6.5 x 4 mile

  = 26 miles. [answer]