5.6 online — answers

• Natuurkunde / Scheikunde
• Middelbare school
• vwo
• Leerjaar 1

Before you do the questions:

1. You are setup in a group through zoom.
2. One of you shares your screen with the presentation on it.
3. Set lessonup to presentation mode.
4. One of you writes down the answers you come to in a word document (if this isn't possible, aks mr. Brands for help)
5. Now you're ready, start the questions

What are the steps in the problem solving procedure?

Given

Asked

Formula

Calculation

Answer

The formula of speed

a) What is the unit of speed? m/s

b) What are the two physical quantities in this unit? 

distance and time.

c) What do you have to do with these quantities to calculate speed? distance divided by time.

d)  What is the formula of speed? speed = distance/ time

Now we are starting with the calculations

• Apply the problem solving procedure.
• You're always allowed to use a calculator.

What is the formula of the speed of sound?

speed = distance/time

v = s/t

What is the problem solving procedure?

given

Asked

Formula

Calculation

Answer

Miss Mulder has setup an experiment to measure the speed of sound. Mister Brands stands 686 meters away from her and hits two wooden planks together to produce a loud sound. It takes 2 seconds before Miss Mulder hears the sound. According to the data of this experiment, what is the speed of sound? 

Given:

distance = 686 meters

time = two seconds

Asked

calculate the speed of sound.

Formula

v = s/t

Calculation

v = 686/2 =343 m/s

Answer

the speed of sound is 343 m/s

What is the speed of sound?

look it up to check wether your answer is correct.

In the distance you see a group of people playing volleyball. One player hits the ball, 1.5 seconds later you hear the sound of it. How far away from you are they playing volleyball?

Given:

t = 1.5 seconds

v = 343 m/s

Asked

How far away are they playing volleyball?

Formula

v = s/t.     s = v * t

Calculation

s = 1.5 * 343 = 514.5 m

Answer

They are 514.5 meters away

Natasha sees a lightning flash, it takes 15 seconds before she hears the thunder of it. How far away did the lightning flash occour?

Given:

t = 15s

v = 343 m/s

Asked

How far away did the lightnign occour?

Formula

v = s/t.     s = v * t

Calculation

s = 15 * 343 = 5145 m

Answer

The lihgtning was 5145 meters away

You clap your hands above a well. The well is 50 meter deep. How long does it take before you can hear the echo of the sound of your clap? Use the problem solving procedure.

Given:

s = 50 x 2 = 100m

v = 343 m/s

Asked

How long does it take before you hear the echo?

Formula

v = s/t.     t = s/v

Calculation

t = 100/343 = 0.29 s

Answer

it takes 0.29 seconds before you hear  the eco

7) A jet plane is 10000m above ground, flying at a speed of 250m/s. By the time the sound from the engines has reached you on the ground, how much further has the jet moved forward?

7) A jet plane is 10000m above ground, flying at a speed of 250m/s. By the time the sound from the engines has reached you on the ground, how much further has the jet moved forward?

Given:

s = 10000 m

v sound = 343 m/s

v jet = 250 m/s

Asked

How much further has the jet moved forward?

Formula

v = s/t

t= s/v

s = v*t

Calculation

t = s/v sound = 10000/343 = 29s

s = v jet * t = 250 * 29 =7250 m

Answer

The Jet has move 7250 meters, which is 7,25 km in this time.

1) Runners in the 100-metre dash have complained that the runner nearest the gun has an unfair advantage.

a. What might this advantage be?

b. What time difference would there be between runners hearing the pistol?

c. Humans have a reaction time of 0.1s, would the difference be important enough to change where the starter sits?

a. That they hear the gun before the other players.

b. 

Given

s player 1 = 10 m

s player 8 = 15 m

v = 343 m/s

Asked

the time difference

Formula

v = s/t

t = s/v

Calcualton

t player 1 = 10/343 = 0.29 s

t player 2 = 15/343 =0.43 s

Time difference = 0.43 - 0.29 = 0.14 s

Answer

The time differece is 0.15 seconds

C.  yes, because the time difference is larger than 0.1 s