Forces and generating force
Name a force
Gravity, air resistance/drag, friction etc.
State Newton's third law.
Every action has an equal and opposite reaction.
True or false: tucking during a somersault increases moment of inertia
False.
Define concervation of momentum
Total momentum before a collision = total momentum after a collision.
Distance / time = ?
Speed
What force acts horizontally, and which force acts vertically?
H = air resistance.
V = gravity.
What is the formula for Newton's second law?
Force = mass x acceleration.
Momentum = ? x ?
Mass x velocity.
True or false: moment of inertia is increased when giving a child a long, heavy bat.
True.
What are the 3 factors affecting projectile motion?
Speed, height and angle of release.
What does the "N" in FONTS refer to?
Using as many body parts as possible.
How does Newton's third law apply to jumping on a trampoline?
Athlete applies a force to the trampoline (action) and trampoline exerts an equal and opposite force on the athlete (reaction).
Throughout a dive, angular momentum...
Remains constant i.e. does not change.
Define impulse and provide the equation for impulse
Impulse is a change in momentum. Impulse = force x time.
Inertia is directly proportional to...
Mass.
What does the "T" in FONTS refer to?
Each body part must be accelerated once the previous body part reaches maximal acceleration (timing).
A stationary player (50 kg) and a 45 kg player running at 5 m/s collide. Who has the most momentum? What should the other player do to have a better outcome?
45 kg player has the most momentum.
The other player should increases their velocity.
True or false: when catching a ball, impulse increases.
False.
Explain conservation of momentum during ten-pin bowling.
Total momentum before collision = total momentum after the collision.
Momentum = mass x velocity.
The ball has high momentum (high mass and velocity), pins have zero momentum. When the ball hits the pins, the pins gain significant momentum, causing them to be knocked over and the ball gradually decreases momentum to zero.
Provide 3 ways an athlete can increase their stability
Increase their base of support, lower their centre of gravity and keep their line of gravity within their base of support (centrally).
How can an athlete use summation of momentum when throwing a ball?
Must discuss any 3 of FONTS.
Define Newton's second law
A force applied to an object will produce acceleration in the direction that the force is applied, that is directly proportional to the size of the force and inversely proportional to its mass.
Explain why giving a pro baseball player a longer bat is advantageous by referring to angular momentum.
Angular momentum is the amount of angular motion possessed by a body.
Angular momentum = moment of inertia x angular velocity. Moment of inertia = mass x radius².
A heavier and longer bat has more mass and a larger radius which will increase the bat’s moment of inertia. If the batter can swing it at the same angular velocity, it will increase the bat’s angular momentum.
An increased angular momentum will transfer to the ball, causing the ball to fly further and increasing the chance of scoring a home run.
Impulse is a chance in momentum (impulse = force x time). When landing, the time the force is applied will increase, decreasing the overall force. This reduces the risk of injury.
Explain when an athlete might be positively accelerating, negatively accelerating and experiencing zero acceleration during a game of basketball
Example response (other examples may also be correct):
Positively = running down court.
Negatively = slowing down as they prepare to shoot.
Zero = standing still on the free-throw line.