Theme A - A.1, A.2, 2.3 - Mechanics

Question 1

What are vectors and scalars?

Answer 1

Vectors have magnitude and direction while scalars only have magnitude.

Question 2

Ax(horisontal component)=? Ay(vertical component)=?

Answer 2

Ax = Acos θ, Ay=Asin θ

Question 3

What is a force?

Answer 3

An interaction between bodies that can change motion or change shape and size of a body.

Question 4

What is the concept of the field used to explain?

Answer 4

Non-contact forces.

Question 5

What is gravitational force?

Answer 5

All bodies with mass exert a force on other bodies. This is gravitational force.

Question 6

What is weight?

Answer 6

The pull of gravity on a body.

Question 7

What is the normal force?

Answer 7

The force that acts on a body that is perpendicular to the surface in contact with the body. I

Question 8

What is the frictional force?

Answer 8

A force between two surface when in contact. It opposes motion.

Question 9

What are the two types of friction?

Answer 9

Static, which acts on bodies at rest, and dynamic, which acts on bodies in motion.

Question 10

What is tension?

Answer 10

The force experienced by a rope (or wire, etc.) attached to a fixed point when the rope is pulled from the other end, or the force experienced by a rope when it is pulled from both ends. Usually, an opposition to forces in one direction

Question 11

What is hooke’s law?

Answer 11

The restoring force acting to return a spring to its original length is proportional to the extension of the spring.

Question 12

What is viscous drag force?

Answer 12

The resistive force opposition motion in a fluid. It depends on the viscosity of the fluid.

Question 12

What is viscosity?

Answer 12

Describes the fluids resistance to flow

Question 12

What is buoyancy(upthrust)?

Answer 12

The force exerted by a fluid on an object partly or wholly immersed in the fluid that counteracts the weight of the body.

Question 13

What causes buoyancy?

Answer 13

The difference in pressure between the top and bottom of the body.

Question 13

What is the archimedes principle?

Answer 13

The buoyancy experienced by a body immersed in a fluid is equal to weight of fluid displaced.

Question 14

What is Newton’s first law?

Answer 14

A body that experiences zero resultant force wil remain at rest or continue to move at a constant velocity. It is said to be in equilibrium.

Question 15

What is inertia?

Answer 15

The tendency of bodies to keep their orignal state.

Question 16

What is Newton’s second law?

Answer 16

The resultant force is the rate of change of momentum.

Question 17

What is Newton’s third law?

Answer 17

Every action has an equal and opposite reaction. The forces act on seperate bodies.

Question 18

Steps for solving a net force problem?

Answer 18

1. Make a diagram and choose the direction that will be taken as positive
2. Make a free-body diagram
3. Find the net force by looking at the free-body diagram
4. Set the net force equal to ma
5. Solve for what is unknown

Question 19

What is momentum?

Answer 19

The product of mass and velocity.

Question 20

What is the law of conservation of momentum?

Answer 20

If no resultant force is acting, the initial momentum of a system is equal to the final momentum of a system(momentum is conserved).

Question 21

What is impulse?

Answer 21

The change in momentum. It is usually caused by collision or explosion.

Question 22

How do we find the impulse on a force time graph?

Answer 22

It is the area under the curve.

Question 23

Describe elastic collisions.

Answer 23

The total kinetic energy is conserved. The total kinetic energy before and after the collision remains the same.

Question 24

What