Chapter 1 - Kinematics

Question 1

Kinematics

Answer 1

Study of motion without looking at forces causing the motion

Question 2

Terms used to describe motion (5)

Answer 2

Distance, displacement, speed, velocity, acceleration

Question 3

Distance

Answer 3

Actual path followed by a moving object
Scalar quantity measured in metres (m)

Question 4

Displacement

Answer 4

Shortest distance between 2 points (straight line), distance travelled in a particular direction
Vector quantity measured in (m)

Question 5

Motion in a circle

Answer 5

Distance around full circle is 2πr
Displacement around full circle is 0
Velocity is 0
Distance from opposite halves is πr
Displacement is 2r

Question 6

Average Speed

Answer 6

Scalar quantity measured in ms-1
Usually changes unless an object is moving at a constant speed, so we take an average

Question 7

Velocity

Answer 7

Vector quantity measured in ms-1

Question 8

Acceleration

Answer 8

Rate of flow of velocity
Vector quantity measured in ms-2

Question 9

Circular motion

Answer 9

movement of an object along the circumference of a circle or rotation
along a circular path. This motion occurs when the vectors of velocity and acceleration are
constantly perpendicular.

Question 10

Projectile motion

Answer 10

form of motion in which an object or particle (called a projectile) is thrown near the earth’s surface, and it moves along a curved path under the action of gravity only. The only force of significance that acts on the object is gravity, which acts downward to cause a downward acceleration.

Question 11

Terminal velocity

Answer 11

highest velocity attainable by an object as it falls through a fluid such as air or oil.

Question 12

Newton’s laws of motion

Answer 12

three physical laws which provide relationships between the forces acting on a body and the motion of the body.

Question 13

Newtons 1st law

Answer 13

States that an object in motion continues to move with uniform velocity, an object at rest stays at rest, unless the object is acted upon by a resultant force

Question 14

Inertia

Answer 14

tendency of an object to resist changes in its state of motion

Question 15

What can be deduced from Newtons 1st law (3)

Answer 15

Inertia - tendency of an object to resist changes in its state of motion
An object can move without forces acting on it
If an object is at rest/moving with constant velocity then all forces acting in any direction have a resultant of 0

Question 16

Instantaneous speed

Answer 16

Speed of an object measured over a very short period of time

Question 17

Resultant

Answer 17

Single vector formed by adding together 2 or more vectors

Question 18

Laboratory measurements of acceleration (3)

Answer 18

Light gates - computer records first interrupt as card passes through the beam of the light gate. Length of interrupt determines the initial speed. Same is done for second light gate. Computer also records time between the measurements. Calculations can now be done to determine the acceleration

Ticker timer - tape divided into sections (5 dots per section), interval between each adjacent dot is 0.02s therefore each section represents 0.10s. Length of each section gives displacement in 0.10s

Motion sensor

Question 19

Uniform acceleration

Answer 19

When the change in velocity of an object is the same in the same time period

Question 20

Non-uniform acceleration

Answer 20

When the velocity of an object changes by different amounts in the same period of time

Question 21

When are SUVAT equations used

Answer 21

Uniform acceleration

Question 22

What can help you visualise the effect of grain a moving object

Answer 22

A multi-flash photo, it shows the object at equal intervals of time

Question 23

Free fall

Answer 23

When an object accelerates due to gravity in the absence of any other forces such as air resistance

Question 24

Laboratory measurements of g (gravity) (3)

Answer 24

Electronic timer
Ticker-timer
Light gate

Question 25

Measuring g using an electronic timer

Answer 25

Steel ball bearing is held by an electromagnet. When current to the magnet is switched off, the ball begins to fall and an electronic timer starts. The ball falls through a trap door, breaking the circuit and stopping the timer. Take several measurements of t for different values of h.

Question 26

Measuring g using a ticker-timer

Answer 26

A weight attached to tape falls, pulling the tape through a ticker timer. This is not an ideal method due to the friction between the tape and the ticker timer

Question 27

Component

Answer 27

The effect of a vector along a particular direction