An ant climbs to the very end of the second hand on a wall-mounted clock at exactly 9:15:00. The second hand is 13.5 cm long. When the time is exactly 9:17:30, (a) what distance did the ant travel? (b) What is the ant‟s displacement at this time? (c) What was the ant‟s average speed? (d) What is the ant‟s average velocity at this time? (e) At what time would the ant have traveled a distance of 100. M (give your answer to the nearest second).

Explanation:

a) The second arm measures the minutes. The difference between 9:17:30 and 9:15:00 is 2 minutes 30 seconds. This means the second arm would have revolved 2.5 times.

The circumference = 2πr= 2π(13.5 cm) = 84.823 cm

Distance = 2.5 × 84.823 cm = 212 cm = 2.12 m

b) Displacement of an object is the shortest distance between the initial and final point. Since the second arm revolves 2 and half times, we use only the half times (a semicircle)

Displacement for semicircle = 2r = 2(13.5) = 27 cm

c) Average speed = distance / time

time = 2 minutes 30 seconds = 150 seconds

Average speed = 212 cm / 150 s = 1.41 cm/s

d) Average velocity = displacement / time = 27 cm / 150 s = 0.18 cm/s

e) number of revolutions = 100 m / circumference = 100 m / 0.848 m = 117.92

but 1 revolution = 1 minute

117.92 revolution = 117 minutes 55 seconds = 1 hour 57 minutes 55 seconds

Hence the time would be: 11:12:55

the answer is a)

mark brainliest

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.