Thursday, August 14, 2008
The weight is given by mass multiplied by gravitational field.
When we holding a weight in a spring balance it shows the reading 9.8kg is its mass is 1 ? Is a substance of 1kg (as saying normal) have mass (1/9.8) ???
posted by S @ 9:44 PM
4 Comments :
gravitational field and acceleration due to gravity(g=9.8 m/s2)are entirly different quantities. "weight=mass * g(acceleration due to gravity) " now comes answer to ur ques.spring balance measures weight and kilogram is a unit of mass.when ur spring balance reads 9.8 kg it means mass of the body is 9.8 kg.mind it, it is not weight.now cums the question why spring balance is measuring mass rather than weight......because the scale of spring balance is calibrated to measure mass i.e. it is already divided by g.
is mass is measured only in the presence of a field?
mass:is the total material content of the body.it remains same irrespective of the field.i.e,mass of the body remains same whether u go to moon or mars and even in space where field is zero.
weight:it is the force by which body is actracted towards the centre of the heavenly body(earth,moon,mars,etc.)therefore depends on acceleration due to gravity of that heavenly body.in other words depend on field. ex a body whose weight at earth is"w" will weigh "w/6" at moon and will have zero weight in space.because acceleration due to gravity at moon is 1/6 times that of earth and zero in space.
@z.zain "the scale of spring balance is calibrated to measure mass" ??
Spring balance changes its reading due to the weight (force) of the body. If we measure a body using spring balance, it shows different reading in earth and moon..... but a common balance shows same reading..