NAME: ________________Answer Key_____________________
UNITS: Force = Newtons (N)
Mass = Kilograms (kg)
Newton’s Laws Examples
Acceleration = Meters per Second2 (m/s/s)
Newton’s Law 1: Inertia
1. If a soccer ball has a mass of 100g, what force would a soccer player need to apply to overcome
the ball’s inertia and accelerate the ball? (100g = 1N)
Mass = Inertia
Answer = >1N
Mass = 100g so Inertia = 100g
You need a force > 100g to overcome 100g of inertia so 100g = 1N
2. If a basketball player has a mass of 50kg, what force would a player setting a screen on them
need to apply to overcome their inertia? (0.1kg = 1N)
50kg = inertia
Answer = >500N
0.1kg = 1N so 500N = 50kg
3. If a running back has a mass of 75kg, what force would a middle linebacker have to apply to the
running back to overcome his inertia? (0.1kg = 1N)
75kg = Inertia Answer = >750N
0.1kg = 1N so 750N = 75 kg
4. If a softball has a mass of 75g, what force would a softball player have to apply to the ball to
overcome its inertia? (100g = 1N)
75g = Inertia
Answer = >0.75N
100g = 1N so 75g = 0.75N
NAME: ________________Answer Key_____________________
Newton’s Laws Examples
Newton’s Law 2: Force(N) = Mass (kg) x Acceleration (m/s/s)
5. What force would a soccer ball apply to a goalie if it were accelerating at 5m/s/s and has a mass
of 100g? Would this be enough to overcome the inertia of a soccer player if their mass was 50kg?
F = Mass x Acceleration so F= 100g x 5m/s/s
F = 100 x 5
F = 500N
OR Since mass was supposed to be in kg F=0.1 x 5  F = 0.5N
6. What force would a middle linebacker apply to the running back if the middle linebacker
accelerated at 5m/s/s and had a mass of 80kg? Do you think this would be enough force to
tackle the running back?
F = Mass x Acceleration
F = 80kg x 5 m/s/s
F = 400N
7. What would the acceleration be on a basketball if a player passed it with a force of 50N and it
had a mass of 150g? (1N = 100g)
F = Mass x Acceleration so F/M = acceleration
F/M = A  50N/150g = 0.333 m/s/s
OR Since mass was supposed to be in kg…
F/M = A  50N/0.150kg = 333.333m/s/s
8. What would the mass of a softball be if it accelerated at 10m/s/s with a force of 25N?
F = Mass x Acceleration so F/A = M
F/A = M  25N/(10m/s/s) = 2.5kg
NAME: ________________Answer Key_____________________
Newton’s Laws Examples
Newton’s Law 3: Equal and Opposite Actions
9. If a soccer ball hits a goalie at 10m/s/s and the soccer ball has a mass of 100g, what would the
force acting on the soccer ball be immediately after hitting the goalie?
Every action has an equal and opposite Reaction so…
F = M x A  F = 100g x 10m/s/s  1000N
OR is doing mass in kg…
F = M x A  F = 0.1 x 10m/s/s  1N
10. If a middle linebacker traveled west at 5m/s/s with a mass of 80kg and a running back traveled
east at 6m/s/s with a mass of 75kg, what would the force acting on the middle linebacker and
running back be and which direction would the collision go?
Middle Linebacker:
Running Back:
F=MxA  F = 80kg x 5m/s/s  FML = 400N
F=MxA  F = 75kg x 6m/s/s  FRB = 450N
400N  West
East  450N
850N on Both collision would go East (with the net force)
11. If a basketball player traveling at 2m/s/s to the west with a mass of 150kg catches a ball with a
mass of 150g traveling at 5m/s/s heading east, what will the force be on both the player and the
ball and which direction will they both go after the collision?
Basketball Player:
Basketball:
F=MxA  F = 150kg x 2m/s/s  FBP = 300N
F=MxA  F = 0.150kg x 5m/s/s  FBB = 0.75N
300N  West
East 0.75
300.75N on Both collision would go West (with the net force)
12. If a softball bat has a mass of 300g traveling at 10m/s/s to the north and a softball has a mass of
75g and travels at 5m/s/s to the south, what would the force acting on the ball and bat be after
the collision and which direction would the collision go?
Bat:
Softball:
F=MxA  F = 0.3kg x 10m/s/s Fsbb = 3N
F=MxA F = 0.075kg x 5m/s/s Fsb = 0.375N
3N  North
South0.375
3.375N on Both collision would go North (with the net force)