Forces & Newton's Laws
This term describes two forces that are equal in size but opposite in direction so the net force is zero.
What is Balanced Force
How do you calculate speed?
What is dividing distance by time.
Name the three methods of thermal energy transfer.
If forces acting on an object are balanced, what is the net force? Choose the letter: a) Greater than zero b) Zero c) Less than zero d) Equal to the mass of the object
What is b.) Zero
What is the formula for velocity?
What is Velocity = Distance / Time with a direction
According to Newton's First Law, an object at rest will stay at rest unless acted upon by this kind of force.
What is Unbalanced
Calculate the speed when a car travels 150 kilometers in 3 hours. Show your work and include units.
S=D/T
S=150km/3hr
What is S=50km/hr
Which method of thermal energy transfer involves the movement of fluids?
What is convection
What does a horizontal line on an distance vs time graph indicate?
What is The object is at rest (no movement)
What is the velocity of an object that is moving 6 meters in 2 seconds east?
What is 3 m/s east
If an object has unbalanced forces acting on it, what will happen to its motion?
What is the object will stop moving
If a student walks 20 meters in 4 seconds, what is the student's average speed? Show the calculation.
S=D/T
S=20m/4s
What is S=5m/s
Explain how conduction transfers thermal energy.
What is through direct contact
Given a motion graph where an object moves 20 cm in the first 2 s, remains at rest from 2–6 s, moves 15 cm from 6–12 s, rests 12–18 s, and moves 15 cm from 18–20 s, calculate the average speed for the interval 6–12 s. Show work.
S=D/T
S=15cm/6s
What is S=2.5cm/s
Distance = 20 meters Time = 4 minutes Direction = south What is the velocity of this object?
What is 5 m/s south
A box has a 10 N push to the right and a 4 N push to the left. What is the net force and which direction will the box accelerate?
What is 6N to the right
What is the difference between speed and velocity?
What is speed is how fast something is going and velocity is how fast something is going plus the direction is going.
An ice cube melts in a liquid which decreases the thermal energy of the liquid. What happens to the thermal energy that is lost by the liquid? How can you show that the thermal energy of the liquid water decreases as the ice melts?
What is the thermal energy gets transferred from the liquid to the ice. You can show that the thermal energy decreases by measuring the temperature with a thermometer.
A particle moves along a line so its positions at equal time intervals are: 0 cm (t=0), 20 cm (t=2 s), 20 cm (t=6 s), 35 cm (t=12 s). Compute the average speed between t=6 s and t=12 s. Show work and units.
D=55cm
T=18s
S=D/T
S=55cm/18s=3.06cm/s
An object travels 25 meters in 2 seconds east. What is it's velocity?
What is 12.5 m/s east (must include direction!)
Describe (in 2–3 sentences) a real-life example of Newton's First Law for an object "in motion" and explain the forces involved.
Answer will vary. At teacher discretion
A runner covers three sections: 60 m in 6 s, then stops for 4 s, then runs 120 m in 12 s. Calculate the average speed for the whole trip (use the total distance divided by total time). Show the work.
D=60m+0m+120m=180m
T=6s+4s+12s=22s
S=D/T
What is S=180m/22s=8.18m/s
Two metal cubes are at different temperatures: Cube A at 80∘C and Cube B at 20∘C. They are placed in contact and reach thermal equilibrium. What will their final temperature be (assume equal masses and the same material, so heat capacity is the same)? Show your reasoning and calculation.
What is 50∘C
80+20=100
100/2=50
Which of these tables shows the correct average speed for each section of the graph? (Teacher will show or draw the graph from the worksheet; students must choose one table).
What is A?
A pink alien moved south in it's spacecraft 2 km at a rate of 20 m/s. How much time did it take him to do this in seconds?
What is 100s