If the velocity of a sailboat changes from 4 m/s to 2 m/s over a period of time, what is true of the sailboat's acceleration?
A. it is positive
B. it is negative
C. it is equal to zero
D. it is equal to 2 knots/hr
Answer: B. it is negative
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Biomechanics Chapter 10
- At the apex of the trajectory of a projectile, vertical velocity is at its maximum.
- Toddlers exhibit more kinematic variability than adults during walking.
- If air resistance is disregarded, the horizontal component of a projectile is constant.
- The vertical acceleration graph of a ball tossed into the air will follow a parabolic path.
- Although elite sprinters display improved kinematics over non-elite sprinters, elite 1500-m runners do not display distinguishable kinematic differences over other skilled runners.
- The form, pattern, or sequencing of movement with respect to time defines __________.
- In the absence of air resistance, the horizontal acceleration of a projectile is always equal to _________.
- The highest point in the trajectory of a projectile is the ___________________.
- A _________ is a body in free fall subject only to the forces of _______ and ____________.
- When acceleration is 0, velocity is _________.
- In the formula v2 = v1, what is known about acceleration?
- The laws of constant acceleration can be applied to which of the following?
- Which of the following represents horizontal acceleration of a projectile?
- Which of the following represents vertical acceleration of a projectile?
- Why do elite long jumpers have take-off angles far less than the optimal 45°?
- The shape of a projectile's trajectory is influenced by which of the following?
- Neglecting the effect of air resistance, which of the following is/are true regarding the horizontal component of projectile velocity?
- Which of the following is/are true regarding the apex in the trajectory of a projectile?
- Which of the following components of projectile is affected by gravity?
- The negative sign in front of the acceleration due to gravity (-9.81 m/s2) can mean which of the following?
- What quantity is calculated as the inverse of speed?
- Why does running downhill tend to increase running speed?
- What factor(s) distinguishes elite cross-country skiers from non-elite performers?
- The meter is the unit of measurement for which of the following?
- Which of the following is/are used to indicate direction of displacement?