ACT Science data representation passages review

What is Newton's first law of motion?

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by a net external force.

Fill in the blank: Force equals mass times ____.

Acceleration: $\displaystyle F = ma$.

True or False: An object can have force without motion.

True - Forces can exist even when an object is stationary.

What is inertia?

The tendency of an object to resist changes in its state of motion.

Compare mass and weight.

- Mass: Amount of matter (kg) - Weight: Force of gravity on mass (N)

What is the formula for acceleration?

Acceleration is calculated using: $\displaystyle a = \\frac{F}{m}$.

Cause → Effect: A greater mass results in ____ acceleration.

Less acceleration for the same force applied.

What does Newton's second law state?

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

True or False: All forces act in pairs.

True - According to Newton's third law, for every action, there is an equal and opposite reaction.

What forces are acting on a falling object?

Gravity pulls it down; air resistance opposes its motion.

Fill in the blank: The unit of force is the ____.

Newton (N).

How does friction affect motion?

Friction opposes the direction of motion, slowing objects down.

Define kinetic energy.

Kinetic energy is the energy of an object due to its motion, calculated as $\displaystyle KE = \\frac{1}{2}mv^2$, where m is mass and v is velocity.

What is potential energy?

Potential energy is stored energy based on an object's position or configuration, commonly gravitational potential energy: $\displaystyle PE = mgh$, with m as mass, g as gravity, and h as height.

True or False: Work is done when a force moves an object.

True. Work is calculated as $\displaystyle W = Fd$, where F is the force applied and d is the distance moved in the direction of the force.

Kinetic vs. Potential Energy.

- Kinetic: Energy of motion - Potential: Stored energy Both are forms of mechanical energy.

Fill in the blank: Work is done when a force acts on an object and causes it to ___.

move.

Calculate the work done by a 10 N force moving an object 5 meters.

Work = Force x Distance = 10 N x 5 m = 50 J (Joules).

Relationship between work and energy.

Work done on an object increases its energy. If work is done against gravity, potential energy increases.

What does it mean for energy to be conserved?

In a closed system, total energy remains constant. Energy can transform from one form to another, but cannot be created or destroyed.

True or False: A stationary object has kinetic energy.

False. A stationary object has zero kinetic energy because its velocity is zero.

List units of work.

- Joules (J) - Newton-meters (N·m) - Foot-pounds (ft·lb)

What is gravitational potential energy?

It is the potential energy held by an object because of its height above the ground, given by the formula $\displaystyle PE = mgh$.

Cause → Effect: Increasing an object's height affects its energy how?

Increasing height increases gravitational potential energy, resulting in higher stored energy.

What does a distance vs. time graph show?

It shows how distance changes over time. - Slope = speed - Horizontal line = no movement.

True or False: A steeper slope indicates lower speed.

False. A steeper slope indicates higher speed.

Fill in the blank: Velocity is the rate of change of _____ with respect to time.

displacement.

What does the area under a velocity vs. time graph represent?

It represents the displacement. - Area = base × height. - Units: (m/s) × s = meters.

Cause → Effect: Increasing the force on an object will result in what?

Higher acceleration. - According to Newton's second law: $\displaystyle F = ma$.

How can you determine average speed from a graph?

Use the formula: Average speed = Total distance / Total time.

What is a potential energy graph?

It shows potential energy changes at different positions. - Higher position = higher potential energy.

Compare kinetic and potential energy in motion.

Kinetic energy: energy of movement. Potential energy: stored energy due to position.

True or False: A flat line on a speed vs. time graph indicates constant speed.

True. A flat line means speed does not change.

What does a negative slope indicate on a distance vs. time graph?

It indicates that the object is returning to the starting point. - Slope = negative value.

How is energy conserved in a closed system?

Total energy remains constant. - Kinetic + Potential = Constant.

Calculate the speed if distance is 150 miles and time is 3 hours.

Speed = distance/time = $\displaystyle \frac{150 ext{ miles}}{3 ext{ hours}} = 50 ext{ mph}$.