Athick wood slab = 0.2 w/m. k and = 1.28 × 10−7 m2 /s) that is initially at a uniform temperature of 25°c is exposed to hot gases at 550°c for a period of 300 sec. as a results of the process, the wood slab is continuously being heated supplied with a heat flux of 13 kw/m2 . if the ignition temperature of wood is 450°c, determine if the wood will ignite.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

it was given as a lesson and guide for prayer.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.