Week 7 Lesson 2

Week 7 Lesson 2

watch the video and prepare for the Questions to follow

Open Ended

What is the formula to calculate speed ?

Multiple Choice

Which Formula should be used to Calculate his speed?

• S=D/T

• W=m x g

• F=m x a

Multiple Choice

Note, convert time into seconds when needed

Using the formula Speed=Distance/Time. Calculate the speed of the following: A freefall jumper jumps out of a building, he is 90 meters above the ground, he takes 3 minute to reach the ground. Use the formula to calculate his speed. Remember to convert certain values when calculating.

Which answer has the formula ,values converted and answered correctly ?

• S=D/T: 90m/3minute = 30m.s, the diver’s speed is 30m.s

• S=D/T: 30m/120s= 0.25m.s, the diver’s speed is 0.25m.s

• S=D/T: 90m/180s=0.5m. s, the diver’s speed is 0.5m.s

• The diver’s speed is 100m.s

Multiple Choice

The Gravitational Force on the moon is the same as on Earth

• False

• True

Multiple Choice

If you have a mass of 56kg on earth , what will your mass be on the the moon ?

• 23kg

• 56kg

• 65kg

• depends on the gravitational forces

Multiple Choice

Using the formula W=m x g ( gravity is 10m/s2 on earth), Calculate the weight of a 50kg object on earth? choose the correct answer

• W=m x g : 50kg x 10m/s2=500N

• W=m /g: 50kg /10m/s2=5N

• W=m x g 50kg x 10m/s2=50N

Multiple Choice

In the formula P=W / T, Time has an SI unit in seconds (s)

• False

• True

Multiple Choice

Note, convert time into seconds when needed

Power=work/time: A small motor in a car does 24000J of work in 4minutes. What is the power of the motor in watts? (use the formula Power=work/time remember to convert certain values where needed) (choose the correct calculation below)

• P=W/T: 24000j/4minutes= 6000w (the motor has 6000 watts of power)

• P=W/T: 24000j/240s= 100w (the motor has 100 watts of power)

• P=W/T: 24000j/120s= 200w (the motor has 200 watts of power)

Multiple Choice

This material would cause a shadow to form on the other side if a light was to shine on it

• Transparent

• Translucent

• opaque

Open Ended

What did you find easy from this lesson and what do you want to have further explained ?

Multiple Choice

From the previous slide which material would be best to replace the window ?

• Translucent

• Transparent

• opaque