Chapter 1.2 - Scalars and vectors.

Question 1

Explain the difference between a scalar and vector. {2}

Answer 1

Scalar has magnitude only {1}

Vector has magnitude amd direction {1}

Question 2

A student states that kinetic energy is a vector quantity, cecause it involves velocity, and velocity is certainly a vector. However, another student says that kinetic energy is a scalar. The second student os correct. Explain why.

Answer 2

All energies are scalars or;

Squaring removes sence of direction or;

Energy has magnitude only.

Question 3

Three laws must hold true for a body which is static. What are these 3 laws?

Answer 3

ΣM = 0

ΣF_V = 0

ΣF_H = 0

Question 4

The following are a list of physical quantities.

Which are vectors?

Energy

Force

Temperature

Acceleration

Distance

Answer 4

Force

Acceleration

Question 5

State the difference between a scalar and vector {1}.

Answer 5

Vector has direction, scalar doesnt. {1}

Question 6

Express the respective values of Fx and Fy from the image below.

Answer 6

Fx = F cos θ

Fy = F sin θ

Question 7

State whether power is a scalar or vector quantity.

Answer 7

Scalar quantity as direction is not important or;

both work / energy and time are scalars

Question 8

Explain the difference between distance and displacement. {1}

Answer 8

Displacement has and implied direction, distance doesnt. {1}

Question 9

Is electrical current a scalar or vector quantity?

Answer 9

Vector.