physics midterm

What is Kinematics?

The study of motion without considering the forces that cause it.

What is Distance?

Total path traveled; scalar quantity.

What is Displacement?

Straight-line change in position with direction.

What is a Vector quantity?

A quantity with magnitude and direction.

Examples of vectors

Velocity, displacement.

What is a Scalar quantity?

A quantity with magnitude only.

Examples of scalars

Distance, speed.

What does the slope of a position-time graph represent?

Velocity.

What does the slope of a velocity-time graph represent?

Acceleration.

What does a horizontal line on a velocity-time graph indicate?

Zero acceleration (constant velocity).

When is average velocity equal to instantaneous velocity?

When velocity is constant.

How can an object accelerate without speeding up?

Slowing down or changing direction at constant speed.

Why does velocity change on a circular path?

Changes because direction changes.

What does negative acceleration mean?

Acceleration opposite motion (slowing down).

What is the displacement for a round trip?

Zero, because final and initial positions are the same.

How do you identify the greatest speed on a velocity-time graph?

Line farthest from zero.

How do you identify the greatest acceleration on a velocity-time graph?

Steepest slope.

How do you determine if an object is speeding up from a graph?

Velocity and slope have same sign.

How do you determine if an object is slowing down from a graph?

Velocity and slope have opposite signs.

How is negative direction motion represented on a velocity-time graph?

Velocity below the time axis.

What is Free fall?

Motion under gravity only.

What is the acceleration due to free fall?

-9.8 m/s² downward.

What is the free-fall distance formula?

d = \frac{1}{2}gt^2

What is the vertical velocity of a projectile at its maximum height?

Zero.

How is car slowing acceleration calculated and interpreted?

a = (vf - vi) / t; negative means slowing.

How do you find initial velocity using kinematic equations?

Rearrange kinematic equations to solve for v_i.

What are the steps to find maximum height?

Set v_f = 0, choose equation, solve for height.

What is the horizontal acceleration of a projectile?

Zero (no horizontal force).

What is the vertical acceleration of a projectile?

Constant due to gravity.

What is the horizontal velocity equation for a projectile?

vx = vi \cos\theta

How do you calculate the time to hit the ground for a horizontal launch?

Use vertical motion: d = \frac{1}{2}gt^2.

How does the initial horizontal speed affect the time to hit the ground?

Hit ground at same time.

What is the horizontal distance formula for a projectile?

x = v_x \cdot t

Describe the path of a package dropped from a plane relative to the plane.

Plane stays directly above the package.

State Newton's First Law.

Objects stay at rest or constant velocity unless acted on by a net force.

State Newton's Second Law and its formula.

F = ma.

State Newton's Third Law.

Every action has an equal and opposite reaction.

What is the net force on an object moving at constant velocity?

Zero.

What is a Normal force?

Support force perpendicular to a surface.

What is the direction of friction?

Opposite motion.

What is Static friction?

Prevents motion.

What is Kinetic friction?

Acts during motion.

Why is it harder to start an object moving than to keep it moving?

Static friction > kinetic friction.

What is the Coefficient of friction?

Ratio of friction force to normal force.

What is the formula for calculating friction force?

Ff = \mu FN.

How does elevator motion affect normal force?

Upward acceleration increases FN; downward decreases FN.

What is Work and its formula?

Force applied over a distance (W = Fd).

When is zero work done?

No displacement or force perpendicular to motion.

What is Kinetic energy?

Energy of motion.

What is Potential energy?

Stored energy.

How does velocity affect kinetic energy?

KE increases with velocity squared.

What is Power?

Rate of doing work.

What are the formulas for Power?

P = W/t or P = Fv.

What is Efficiency and its formula?

Output work / input work \times 100\%.

What is Mechanical advantage?

How much a machine multiplies force.

How does a ramp provide mechanical advantage?

Less force over longer distance; same work.

What kind of energy is stored in a spring?

Stored elastic potential energy.

What is the difference between mass and weight?

Mass is constant; weight depends on gravity.

What are the steps for solving kinematics problems (e.g., for distance)?

List knowns, choose equation, plug in, solve.

What are the steps for solving projectile motion problems?

Break velocity into components, solve vertical for time, use time for range.

What is the difference between balanced and unbalanced forces?

Balanced: no acceleration; unbalanced: acceleration.