Mechanics

Question 1

Equation linking s, u, t & a

Answer 1

S = ut + 1/2at²

Question 2

Gravitational mass vs inertial mass

Answer 2

Both have the same numerical value; only difference is definition & method

Question 3

Gravitational mass definition

Answer 3

A quantity that determines the gravitational force on the object

Question 4

Inertial mass definition

Answer 4

A quantity that determines the acceleration of the object

Question 5

Equation linking v, u, a & t

Answer 5

V = u + at

Question 6

Equation linking s, v t & a

Answer 6

S = vt- 1/2at²

Question 7

Equation linking v, u, a & s

Answer 7

V² = u² + 2as

Question 8

Equation linking s u v & t

Answer 8

S = 1/2(u + v)t

Question 9

Acceleration definition & equation

Answer 9

Rate of change of velocity

A = (v-u)/t

Question 10

What is s?

Answer 10

Displacement

Question 11

Horizontal & vertical motion what remains constant?

Answer 11

Horizontal = constant velocity(negligible air resistance)

Vertical = constant acceleration (-g)

Question 12

Equation for range (horizontal displacement) of projectile

Answer 12

R or s = vcosθt

Question 13

Weight (N) equation

Answer 13

Mass x gravitational field strength

Question 14

Work done unit

Answer 14

Nm (same as joules)

Question 15

Graphical method for determining work done

Answer 15

Area under force x distance graph

Question 16

Power

Answer 16

Work done per unit time

Question 17

Efficiency equation

Answer 17

Useful work out ➗ total energy in

Question 18

Newton’s first law

Answer 18

• When no external forces act on a body (net force=0) the body will either remain at rest (v=0 ms-1) or continue to move with constant speed.

Question 19

Newton’s second law

Answer 19

The rate of change of momentum is directly proportional to the unbalanced force acting on that body and takes place in the same direction

Question 20

Impulse

Answer 20

Change in momentum (mv-mu)

Question 21

Unit of momentum

Answer 21

Ns (same as kgms^-1)

Question 22

Finding the impulse

Answer 22

Graphically: area under the curve of a force/time graph

Change in momentum = force X change in time

Question 23

Perfectly elastic collision

Answer 23

One in which there is no loss of kinetic energy in the collision

Question 24

principle of conservation of momentum

Answer 24

the total momentum of a system is constant provided external force does not act

Question 25

why does drag force increase with speed?

Answer 25

objects encounter more fluid per second and hit it harder

Question 26

velocity of x relative to y

Answer 26

subtract the velocity of y from x

Question 27

size of buoyancy force

Answer 27

weight of fluid displaced

Question 28

condition for a body to be in translational equilibrium

Answer 28

No external force acting on the body

Question 29

what does dynamic friction do

Answer 29

opposes the relative motion between two touching surfaces

Question 30

what does static friction do

Answer 30

STOPS the relative motion between two touching surfaces

Question 31

gravitational field strength exam definition

Answer 31

the force per unit mass experienced by a small point mass placed in the field