Step | Formula / Calculation | Reasoning |
---|---|---|

1 | \text{distances in meters} = [1000, 1000, 1000, 1000] m | Converting the distances for each kilometer of the race to meters. |

2 | \text{times in seconds} = [354, 372, 378, 360] s | Converting the times for each kilometer of the race from minutes to seconds. |

3 | \text{total distance} = \sum \text{distances in meters} = 4000 m, \text{total time} = \sum \text{times in seconds} | Calculating the total distance and total time for the race in standard units. |

4 | \text{average speed} = \frac{\text{total distance}}{\text{total time}} | Calculating the average speed using the total distance and total time in standard units. |

5 | \text{average speed} \approx 2.73 m/s | Evaluating the average speed of the runner in meters per second. |

The average speed of the runner in the 4.0-kilometer race, when calculated using standard units, is approximately 2.73 meters per second.

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- Statistics

Advanced

Mathematical

GQ

You are standing on a bathroom scale in an elevator. The elevator starts from rest on the first floor and accelerates up to the third floor, 12 meters above, in a time of 6 seconds. The scale reads 800N. What is the mass of the person?

- 1D Kinematics, Elevators, Linear Forces

Intermediate

Mathematical

MCQ

- 1D Kinematics, Motion Graphs

Advanced

Mathematical

FRQ

Two students are on a balcony 19.6 m above the street. One student throws a ball vertically downward at 14.7 m/s. At the same instant, the other student throws a ball vertically upward at the same speed. The second ball just misses the balcony on the way down.

- 1D Kinematics

Beginner

Conceptual

MCQ

Which of the following statements about the acceleration due to gravity is TRUE?

- 1D Kinematics, Linear Forces, Projectiles

Intermediate

Mathematical

GQ

There are two cables that lift an elevator, each with a force of 10,000 N. The 1,000 kg elevator is lifted from the first floor and accelerates over 10 m until it reaches its top speed of 6 m/s. What is the mass of the people in the elevator?

- 1D Kinematics, Elevators, Linear Forces

Intermediate

Mathematical

GQ

A person whose weight is 4.92 × 10^{2} N is being pulled up vertically by a rope from the bottom of a cave that is 35.2 m deep. The maximum tension that the rope can withstand without breaking is 592 N. What is the shortest time, starting from rest, in which the person can be brought out of the cave?

- 1D Kinematics, Linear Forces

Intermediate

Mathematical

GQ

A 135.0 N force is applied to a 30.0 kg box at 42 degree angle to the horizontal. If the force of friction is 85.0, what is the net force and acceleration? If the object starts from rest, how far has it traveled in 3.3 sec?

- 1D Kinematics, Linear Forces

Intermediate

Conceptual

MCQ

In which of the following is the rate of change of the particle’s momentum zero?

- Momentum, Motion Graphs

Intermediate

Mathematical

GQ

On a strange, airless planet, a ball is thrown downward from a height of 17 m. The ball initially travels at 15 m/s. If the ball hits the ground in 1 s, what is this planet’s gravitational acceleration?

- 1D Kinematics

Advanced

Mathematical

FRQ

A Corvette is traveling at a constant velocity 30 m/s when it passes a stationary supped up Civic. At that moment, the Civic puts the pedal to the floor and accelerates at 6 m/s^{2}^{.} The Civic eventually catches up to the Corvette.

- 1D Kinematics

2.7 m/s

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Kinematics | Forces |
---|---|

\Delta x = v_i t + \frac{1}{2} at^2 | F = ma |

v = v_i + at | F_g = \frac{G m_1m_2}{r^2} |

a = \frac{\Delta v}{\Delta t} | f = \mu N |

R = \frac{v_i^2 \sin(2\theta)}{g} |

Circular Motion | Energy |
---|---|

F_c = \frac{mv^2}{r} | KE = \frac{1}{2} mv^2 |

a_c = \frac{v^2}{r} | PE = mgh |

KE_i + PE_i = KE_f + PE_f |

Momentum | Torque and Rotations |
---|---|

p = m v | \tau = r \cdot F \cdot \sin(\theta) |

J = \Delta p | I = \sum mr^2 |

p_i = p_f | L = I \cdot \omega |

Simple Harmonic Motion |
---|

F = -k x |

T = 2\pi \sqrt{\frac{l}{g}} |

T = 2\pi \sqrt{\frac{m}{k}} |

Constant | Description |
---|---|

g | Acceleration due to gravity, typically 9.8 , \text{m/s}^2 on Earth’s surface |

G | Universal Gravitational Constant, 6.674 \times 10^{-11} , \text{N} \cdot \text{m}^2/\text{kg}^2 |

\mu_k and \mu_s | Coefficients of kinetic (\mu_k) and static (\mu_s) friction, dimensionless. Static friction (\mu_s) is usually greater than kinetic friction (\mu_k) as it resists the start of motion. |

k | Spring constant, in \text{N/m} |

M_E = 5.972 \times 10^{24} , \text{kg} | Mass of the Earth |

M_M = 7.348 \times 10^{22} , \text{kg} | Mass of the Moon |

M_M = 1.989 \times 10^{30} , \text{kg} | Mass of the Sun |

Variable | SI Unit |
---|---|

s (Displacement) | \text{meters (m)} |

v (Velocity) | \text{meters per second (m/s)} |

a (Acceleration) | \text{meters per second squared (m/s}^2\text{)} |

t (Time) | \text{seconds (s)} |

m (Mass) | \text{kilograms (kg)} |

Variable | Derived SI Unit |
---|---|

F (Force) | \text{newtons (N)} |

E, PE, KE (Energy, Potential Energy, Kinetic Energy) | \text{joules (J)} |

P (Power) | \text{watts (W)} |

p (Momentum) | \text{kilogram meters per second (kgm/s)} |

\omega (Angular Velocity) | \text{radians per second (rad/s)} |

\tau (Torque) | \text{newton meters (Nm)} |

I (Moment of Inertia) | \text{kilogram meter squared (kgm}^2\text{)} |

f (Frequency) | \text{hertz (Hz)} |

General Metric Conversion Chart

Conversion Example

Example of using unit analysis: Convert 5 kilometers to millimeters.

Start with the given measurement:

`\text{5 km}`

Use the conversion factors for kilometers to meters and meters to millimeters:

`\text{5 km} \times \frac{10^3 \, \text{m}}{1 \, \text{km}} \times \frac{10^3 \, \text{mm}}{1 \, \text{m}}`

Perform the multiplication:

`\text{5 km} \times \frac{10^3 \, \text{m}}{1 \, \text{km}} \times \frac{10^3 \, \text{mm}}{1 \, \text{m}} = 5 \times 10^3 \times 10^3 \, \text{mm}`

Simplify to get the final answer:

`\boxed{5 \times 10^6 \, \text{mm}}`

Prefix | Symbol | Power of Ten | Equivalent |
---|---|---|---|

Pico- | p | 10^{-12} | 0.000000000001 |

Nano- | n | 10^{-9} | 0.000000001 |

Micro- | µ | 10^{-6} | 0.000001 |

Milli- | m | 10^{-3} | 0.001 |

Centi- | c | 10^{-2} | 0.01 |

Deci- | d | 10^{-1} | 0.1 |

(Base unit) | – | 10^{0} | 1 |

Deca- or Deka- | da | 10^{1} | 10 |

Hecto- | h | 10^{2} | 100 |

Kilo- | k | 10^{3} | 1,000 |

Mega- | M | 10^{6} | 1,000,000 |

Giga- | G | 10^{9} | 1,000,000,000 |

Tera- | T | 10^{12} | 1,000,000,000,000 |

- Some answers may be slightly off by 1% depending on rounding, etc.
- Answers will use different values of gravity. Some answers use 9.81 m/s
^{2}, and other 10 m/s^{2 }for calculations. - Variables are sometimes written differently from class to class. For example, sometime initial velocity v_i is written as u ; sometimes \Delta x is written as s .
- Bookmark questions that you can’t solve so you can come back to them later.
- Always get help if you can’t figure out a problem. The sooner you can get it cleared up the better chances of you not getting it wrong on a test!

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