Physics- Resultant Forces and Terminal Velocity

Question 1

If more than one force acts on an object their overall effect can be replaced by a single force known as….

Answer 1

the resultant force

Question 2

Balanced Forces- What can be said about the size of the forces on a stationary object?

Answer 2

They are equal in size and are balanced.

Question 3

When you discuss ‘fractionless’ motion for an object which had previously been given a push (eg a bit like an ice hockey puck moving along after being hit), the resultant (overall) horizontal force acting is..

Answer 3

almost 0

Question 4

The motion this seemed to produce was one of a….

Answer 4

onstant speed in a straight line.

Question 5

Forces unbalanced - resultant force is non-zero: The object….

Answer 5

accelerates or decelerates.

Question 6

Forces balanced- resultant force is zero: The object….

Answer 6

remains at rest or continues to move with a steady speed if it is already moving.

Question 7

A resultant force causes…

Answer 7

acceleration or deceleration.

Question 8

The object will accelerate if the resultant force acts with the motion, but it will decelerate if the resultant force acts….

Answer 8

against the motion

Question 9

If the resultant force is zero this means that the acceleration of the object is zero and this therefore means that the object moves at….

Answer 9

a constant speed in a constant direction.

Question 10

The acceleration is……… ……….to the resultant force when the mass of the object is constant.

Answer 10

directly proportional

Question 11

The acceleration is ……….. …………… to the mass when the resultant force is constant.

Answer 11

inversely proportional

Question 12

Resultant force = mass x ……

Answer 12

acceleration

Question 13

Newton’s third law: ‘action and reaction are equal but ………’

Answer 13

opposite

Question 14

A falling object accelerates because a resultant force acts on it. The resultant force is due to the…

Answer 14

gravitational pull between the object and the Earth.

Question 15

We call this force acting on the object its …

Answer 15

weight

Question 16

The weight of an object is proportional to the…

Answer 16

mass of the object.

Question 17

How many newtons of weight act on each kg of mass?

Answer 17

10N/kg

Question 18

……. = mass x gravitational field strength

Answer 18

weight

Question 19

Parachutists make use of air resistance (drag). Drag is a ………. ……. acting on something moving through a gas or liquid (both of these are classified as fluids).

Answer 19

friction force

Question 20

The faster an object moves through a gas or liquid, the ……. the drag.

Answer 20

greater

Question 21

Any object falling through a fluid is affected by drag (fluid friction). The size of the drag depends on what factors?

Answer 21

The speed of the object through the fluid
the size of the object
the shape of the object

Question 22

Why does drag increase the faster you move though a liquid or gas?

Answer 22

great effect of the rubbing of molecules