UPCAT Physics — Kinematics & Speed, Velocity, AccelerationFlash Cards

A jeepney travels 240 meters in 30 seconds. Calculate its average speed.

Formula: Speed = distance/time Step 1: Given - distance = 240 m, time = 30 s Step 2: Speed = 240 m ÷ 30 s = 8 m/s Answer: 8 m/s

What is the difference between speed and velocity?

Speed is a scalar quantity measuring how fast an object moves (magnitude only). Velocity is a vector quantity measuring how fast an object moves AND in what direction (magnitude + direction). Example: A car moving at 60 km/h eastward has speed = 60 km/h and velocity = 60 km/h east.

A tricycle moves 50 meters north in 10 seconds. Find its velocity.

Formula: Velocity = displacement/time Step 1: Given - displacement = 50 m north, time = 10 s Step 2: Velocity = 50 m north ÷ 10 s = 5 m/s north Answer: 5 m/s north (direction is essential for velocity)

A bus increases its speed from 10 m/s to 25 m/s in 5 seconds. Calculate acceleration.

Formula: a = (v_final - v_initial)/time Step 1: Given - v_i = 10 m/s, v_f = 25 m/s, t = 5 s Step 2: a = (25 - 10)/5 = 15/5 = 3 m/s² Answer: 3 m/s²

What does negative acceleration mean?

Negative acceleration (deceleration) means the object is slowing down if moving in the positive direction, or the acceleration is opposite to the direction of motion. Example: A car braking from 60 km/h to 0 km/h has negative acceleration because it's reducing speed.

A motorcycle travels 180 km in 3 hours. What is its average speed in m/s?

Formula: Speed = distance/time Step 1: Convert units - 180 km = 180,000 m, 3 h = 10,800 s Step 2: Speed = 180,000 m ÷ 10,800 s = 16.67 m/s Answer: 16.67 m/s

State Newton's First Law of Motion.

An object at rest will remain at rest, and an object in motion will remain in motion at constant velocity, unless acted upon by an external force. This is also called the Law of Inertia. Example: A book on a table stays at rest until someone pushes it.

A falling coconut accelerates at 9.8 m/s². If it starts from rest, what is its velocity after 2 seconds?

Formula: v = u + at (where u = initial velocity) Step 1: Given - u = 0 m/s, a = 9.8 m/s², t = 2 s Step 2: v = 0 + (9.8)(2) = 19.6 m/s Answer: 19.6 m/s downward

Why do objects fall at the same rate in a vacuum?

In a vacuum, gravity is the only force acting on falling objects, and gravitational acceleration (9.8 m/s²) is the same for all objects regardless of mass. Without air resistance, a feather and a hammer fall at the same rate, as demonstrated on the Moon.

A car decelerates from 30 m/s to 10 m/s in 4 seconds. Find the acceleration.

Formula: a = (v_final - v_initial)/time Step 1: Given - v_i = 30 m/s, v_f = 10 m/s, t = 4 s Step 2: a = (10 - 30)/4 = -20/4 = -5 m/s² Answer: -5 m/s² (negative indicates deceleration)

What is instantaneous velocity?

Instantaneous velocity is the velocity of an object at a specific moment in time. It's the rate of change of position at that exact instant. Example: A car's speedometer shows instantaneous speed at any given moment during the trip.

State the kinematic equation: d = v₀t + ½at²

Distance = initial velocity × time + ½ × acceleration × time² This equation calculates displacement when initial velocity, acceleration, and time are known. Units: d in meters, v₀ in m/s, a in m/s², t in seconds. Used for uniformly accelerated motion.

A stone is dropped from a 45-meter building. How long does it take to hit the ground?

Formula: d = ½gt² (starting from rest, so v₀ = 0) Step 1: Given - d = 45 m, g = 9.8 m/s² Step 2: 45 = ½(9.8)t² → 45 = 4.9t² → t² = 9.18 Step 3: t = √9.18 = 3.03 seconds Answer: 3.03 seconds

What is the difference between distance and displacement?

Distance is the total path traveled (scalar, always positive). Displacement is the straight-line distance from start to end point with direction (vector, can be positive or negative). Example: Walking 100m east then 100m west gives distance = 200m but displacement = 0m.

A basketball player throws a ball upward at 15 m/s. What is its velocity at the highest point?

At the highest point of projectile motion, vertical velocity = 0 m/s Step 1: The ball momentarily stops before falling back down Step 2: Gravity continues to act, but velocity changes direction Answer: 0 m/s (before it starts falling back down)

State Newton's Second Law of Motion with its formula.

The acceleration of an object is directly proportional to the net force and inversely proportional to its mass. Formula: F = ma Where F = force (Newtons), m = mass (kg), a = acceleration (m/s²) Example: A 2kg ball with 10N force has acceleration = 10÷2 = 5 m/s²

A train accelerates uniformly from 5 m/s to 20 m/s over 150 meters. Find the acceleration.

Formula: v² = u² + 2as Step 1: Given - u = 5 m/s, v = 20 m/s, s = 150 m Step 2: (20)² = (5)² + 2a(150) Step 3: 400 = 25 + 300a → 375 = 300a Step 4: a = 375/300 = 1.25 m/s² Answer: 1.25 m/s²

What is uniform circular motion?

Movement of an object in a circle at constant speed. Although speed is constant, velocity changes because direction constantly changes. The acceleration (centripetal acceleration) points toward the center of the circle. Example: A satellite orbiting Earth at constant altitude.

What does it mean when acceleration is constant?

Constant acceleration means velocity changes by the same amount every second. The object gains (or loses) a fixed amount of speed per unit time. Example: Free-falling objects have constant acceleration of 9.8 m/s² - they speed up by 9.8 m/s every second.

A cyclist starts from rest and reaches 12 m/s after traveling 36 meters. Find the acceleration.

Formula: v² = u² + 2as Step 1: Given - u = 0 m/s (from rest), v = 12 m/s, s = 36 m Step 2: (12)² = (0)² + 2a(36) Step 3: 144 = 72a Step 4: a = 144/72 = 2 m/s² Answer: 2 m/s²