Forces in Physics

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What happens to the density of the atmosphere as altitude increases?

It decreases (correct)
It increases
It oscillates
It remains constant

What is the main reason for the difference in pressure between the top and bottom surfaces of a partially submerged object?

The weight of the object itself
The difference in density of the surrounding fluid
The greater pressure on the bottom surface due to the weight of the fluid above (correct)
The shape of the object

What is the term for the resultant force upward experienced by a partially submerged object?

Buoyancy
Friction
Downthrust
Upthrust (correct)

What is the difference between distance and displacement?

Distance excludes direction, while displacement includes it (A) Signup and view all the answers

What is the characteristic of the atmosphere that makes it transparent to solar radiation?

Its composition (C) Signup and view all the answers

What does a sharper gradient on a displacement-time graph represent?

Faster speed (B) Signup and view all the answers

What is the difference between speed and velocity?

Speed excludes direction, while velocity includes it (B) Signup and view all the answers

What can be calculated by drawing a tangent on a displacement-time graph?

Velocity (C) Signup and view all the answers

What does the area under a velocity-time graph represent?

Distance travelled (A) Signup and view all the answers

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

Stationary (B) Signup and view all the answers

What does a negative gradient on a velocity-time graph represent?

Deceleration (C) Signup and view all the answers

What is the reason for the gravitational attraction between two objects?

The mass of the objects (D) Signup and view all the answers

What is the unit of measurement for weight?

Newtons (A) Signup and view all the answers

What is the relationship between the mass of an object and its gravitational field strength?

The mass of an object is directly proportional to its gravitational field strength (A) Signup and view all the answers

Why does a person's weight change when they move to a different planet?

Because the gravitational field strength on the new planet is different (C) Signup and view all the answers

What is the purpose of a force meter, also known as a calibrated spring-balance?

To measure the weight of an object (B) Signup and view all the answers

What is the value of g on Earth?

9.8 N/kg (C) Signup and view all the answers

What is the unit of force in the equation F = ma?

N (A) Signup and view all the answers

What is the term for the measure of how difficult it is to change the velocity of an object?

Inertia (C) Signup and view all the answers

What is the result when a rocket exerts a force on the gases being ejected?

The gases apply a force equal in magnitude but opposite in direction on the rocket. (C) Signup and view all the answers

What is the distance travelled by a vehicle during the time it takes to react to a hazard?

Thinking Distance (C) Signup and view all the answers

What is the factor that affects the braking distance of a vehicle?

All of the above (D) Signup and view all the answers

What is the unit of momentum?

kg m/s (C) Signup and view all the answers

What is always conserved in a collision or explosion with no external forces?

Momentum (D) Signup and view all the answers

What does Newton's Second Law of Motion state?

Force is equal to the rate of change of momentum (A) Signup and view all the answers

What is the purpose of crumple zones in a car?

To absorb energy and increase the time taken for the car to stop (A) Signup and view all the answers

What is the purpose of seatbelts in a car?

To strap the passengers in and reduce the rate of change of momentum (D) Signup and view all the answers

What is the purpose of airbags in a car?

To increase the time taken for the head to stop moving (D) Signup and view all the answers

Why is braking hard dangerous?

Because it increases the rate of change of momentum, causing a large force on the passengers (A) Signup and view all the answers