Our Dynamic Universe

Question 1

Name Scalar quantities

Answer 1

• Speed
• Distance

Question 2

Name Vector quantities

Answer 2

-Velocity
- Displacement
-Acceleration

Question 3

Describe Vector addition

Answer 3

When combining vectors, always add them nose to tail. Draw a scale diagram on the largest scale use an angle measurer. Or work from components to get one Vectorvertical, one Vector horizontal, then use SohCahToa, and Pythagoras Theorem to calculate direction and magnitude of the resultant vector.

Question 4

Describe Terminal Velocity

Answer 4

Terminal Velocity is the maximum velocity an object will reach when in free Fall, this will occur when the Weight is equal in magnitude to the force due to air resistance

Question 5

Describe Free Fall

Answer 5

When an object is in free fall, it will accelerate due to its weight, as its velocity increases the force due to air resistance will also increase. The acceleration will then decrease until it reaches terminal velocity.

Question 6

Describe Tension

Answer 6

Tension is the force experienced at a join between two objects, for example a rope towing a car.

Question 7

Describe apparent weight

Answer 7

Apparent weight is the value of weight displayed on a scale. The value of apparent weight can change if it is viewed when accelerating vertically (e.g. in a lift). Apparent weight is measure in Newtons (N)

Question 8

Describe collisions

Answer 8

Collision is when 2 objects collide together. All collisions follow the law of the conservation of momentum. Momentum and Total Energy conserved

Question 9

Describe Elastic collisions

Answer 9

In an elastic collision the objects will ‘bounce off’ each other or not stick together. Prove elastic collision as total kinetic energy must be conserved during the interaction

Question 10

Describe Inelastic collisions

Answer 10

In an In-elastic collision the objects will ‘stick together. Kinetic Energy must be lost.

Question 11

Describe Explosions

Answer 11

In an explosion 2 objects will diverge in opposite directions; Conservation of momentum must still apply. (Velocity is a vector, backwards is negative)

Question 12

Describe Impulse

Answer 12

Impulse is the measure of the change in momentum. Impulse is measure in Newton seconds

Question 13

Describe Momentum

Answer 13

Momentum is a measure of an objects mass multiplied by its velocity. It is one of the most important things to consider in collisions. Momentum has the unit kilogram meters per second (kgm s-1)

Question 14

Describe conservation of Momentum

Answer 14

In the absence of external forces, the total momentum before a collision must be equal to the total momentum after a collision.

Question 15

Describe Newtons 1st law

Answer 15

Every object will remain at rest, or at a constant velocity, unless acted upon by an external force

Question 16

Describe Newtons 2nd Law

Answer 16

When an unbalanced
force acts on an object Newton discovered that: the direction of the object’s accelerations the same as the direction of the unbalanced force
the magnitude of the object’s acceleration varies in direct proportion with the size of the unbalanced force the magnitude of the object’s acceleration varies inversely with the
mass of the object

Question 17

Describe Newtons 3rd Law

Answer 17

f object a exerts a force on object b, then object b will exert and equal but opposite force on object a