Class Test December'14 Nat 5

Question 1

What is a scalar quantity?

Answer 1

Described by stating its size only.

Question 2

What is a vector quantity?

Answer 2

Described by stating its size and direction.

Question 3

What are the scalar quantities?

Answer 3

distance, speed, mass, time, energy

Question 4

What are the vector quantities?

Answer 4

displacement, velocity, force, acceleration

Question 5

What is distance?

Answer 5

The total distance travelled

Question 6

What is displacement?

Answer 6

The length measured from the start point to the end point in a straight line.

Question 7

What is acceleration and it’s formula?

Answer 7

The change in speed or velocity every second and is measured in metres per second per second.
a= (final velocity - initial velocity) /time
a= v-u/t

Question 8

What can forces be measured with and what are their units?

Answer 8

Newton balance, newtons

Question 9

What is Newton’s 1st Law of Motion?

Answer 9

An object will remain at rest or travel in a straight line at a constant velocity if the forces are balanced.

Question 10

What does acceleration being produced depend on?

Answer 10

The mass of the object, the unbalanced force

Question 11

What is the equation for Newton’s 2nd Law of Motion

Answer 11

Unbalanced force= mass x acceleration

F= ma

Question 12

What is free fall?

Answer 12

The term used when an object is being acted upon only by the force of gravity

Question 13

Describe the forces acting upon a skydiver as he jumps

Answer 13

There is no air resistance, weight is the only force acting on the skydiver (downwards) -maximum acceleration

Question 14

Describe the forces acting upon a skydiver during free fall

Answer 14

There is air resistance but weight (gravity) is still a stronger force ( weight> air resistance) -the acceleration is decreasing

Question 15

Describe the forces acting upon a skydiver at terminal velocity

Answer 15

weight= air resistance. The forces are balanced and the speed is constant -acceleration=0

Question 16

What are all forms of energy measured in?

Answer 16

Joules

Question 17

What is work done?

Answer 17

A measure of the energy transformed. It is equal to the force multiplied by the displacement the force moves. The force and displacement must be measured in the same direction.

Question 18

What is the equation for work done?

Answer 18

Work done= force x displacement

Ew= Fs

Question 19

What is the equation for weight?

Answer 19

Weight= mass x gravitational field strength

W=mg

Question 20

What is Newton’s 3rd Law of Motion?

Answer 20

If object A exerts a force (the action) on object B, then object B will exert an equal, but opposite force (the reaction) on object A.