Physics Unit 1 Practice Quiz

Speed measures how fast an object is moving and does not include a directional component. Displacement, velocity, and acceleration are vector quantities because they have both magnitude and direction.

The SI unit of force is the newton (N). It is defined as the force required to accelerate a 1 kg mass by 1 m/s².

Inertia is the property of an object that causes it to resist changes in its state of motion. This concept is demonstrated in Newton's First Law of Motion.

An object moving at a constant velocity has no change in speed or direction, hence its acceleration is zero. Acceleration is defined as the rate of change of velocity.

A mass balance is designed to measure the mass of an object accurately. Instruments like spring scales measure weight, while thermometers and barometers measure temperature and atmospheric pressure, respectively.

Acceleration is defined as the change in velocity divided by the time over which the change occurs. This formula is essential in analyzing uniformly accelerated motion.

Newton's second law establishes a direct proportionality between the net force acting on an object and its acceleration, with mass as the proportionality constant, expressed by F = ma.

Acceleration is calculated by dividing the change in velocity by the time taken. Here, the change from 0 to 20 m/s over 5 seconds gives an acceleration of 4 m/s².

Work is defined as the product of the force applied to an object and the displacement in the direction of that force. This concept is fundamental when studying energy transfer.

Kinetic energy is the energy an object possesses because of its motion. It depends on both the mass of the object and the square of its velocity.

Using Newton's second law (F = ma), the acceleration is found by dividing the net force by the mass, yielding 50 N / 10 kg = 5 m/s².

Equal and opposite forces cancel each other out, resulting in a net force of zero. This balance of forces means there is no acceleration.

The slope of a velocity vs. time graph shows the rate at which velocity changes, which is the definition of acceleration. This graphical analysis is key in understanding motion.

Momentum is conserved in all collisions provided the system is isolated from external forces. Unlike kinetic energy, which may not be conserved in inelastic collisions, momentum remains constant.

Vector quantities have both magnitude and direction, which distinguishes them from scalar quantities that only have magnitude. This is fundamental in the study of forces and motion.

The law of cosines is used to determine the resultant force when two forces are at an angle. Calculating √(8² + 6² + 2à - 8à - 6à - cos60°) yields approximately 12.2 N.

The maximum height of a projectile is given by H = (v² sin²θ) / (2g). With v = 30 m/s and θ = 45° (sin²45° = 0.5), the height calculates to roughly 23 m.

The period of a mass-spring system is determined by the formula T = 2π√(m/k). Substituting m = 5 kg and k = 200 N/m gives a period of roughly 1.0 second.

By conserving energy on a frictionless incline, the gravitational potential energy converts entirely into kinetic energy. This leads to the equation v = √(2gh), where g is the acceleration due to gravity and h is the height.

At the maximum height, the vertical velocity becomes zero. Using the equation v = u - gt and solving for time, t = u / g, which gives roughly 40/9.8 ≈ 4.1 seconds.