Kinematics

Question 1

Velocity?

Answer 1

Rate of change of displacement

Question 2

Acceleration?

Answer 2

Rate of change of velocity

Question 3

Relationship between s-t, v-t, a-t graphs?

Answer 3

Refer to image 1

Question 4

3 Kinematic equations?

Conditions when using them.

Answer 4

1. s = ut+ 1/2 at [Given]
2. v^2 = u^2 + 2as [Given]
3. v = u + at

Constant acceleration + Motion in straight line

Question 5

Solving qn with kinematic eqns.

Answer 5

1. Diagram
2. Assign +ve direction
3. USATV (Identify unknown)
4. Use eqns (Need 3 of 5 USATV)

Question 6

Special case when no/negligible air resistance or free fall.

Answer 6

a=9.81m/s-2 downwards (For earth)

Question 7

What to do when dealing with ‘Presence of air resistance’?

Answer 7

Refer to image 2

Question 8

Factors affecting terminal velocity? (Reach faster)

Answer 8

Lower weight –> (Air resistance = Weight) faster

Larger surface area –> More air resistance –> (Air resistance = Weight) faster

Question 9

2 assumptions made for projectile motion.

Answer 9

1. No air resistance, vert. acceleration = 9.81m/s^2 down

2. No horizontal acceleration

Question 10

[Projectile Motion] Eqns relating to Horizontal

Answer 10

a = 0
u = v
s = ut

Question 11

[Projectile Motion] Eqns relating to Vertical

Answer 11

3 Kinematic Eqns

Question 12

Common quantity of Horizontal and Vertical eqns?

Answer 12

Time (t)

Question 13

Solving qns for projectile motion.

Answer 13

1. Diagram
2. Assign +ve direction (x,y)
3. Resolve inital velocity into Ux and Uy
4. USATV (x+y)

Question 14

a. Special thing that happens at highest point.
b. What can be found from Vx and Vy?
c. Air resistance vs No air resistance?

Answer 14

Refer to image 3

Question 15

Accounting for difference of path with and w/o air resistance

Answer 15

With air resistance, work has to bone done against air resistance, lower vert. and horz. component of initial VELOCITY reduced.

Question 16

General assumption about initial velocity (u)?

Answer 16

u = 0 (Often Uy)