Suppose that an Egyptian farmer claims to have discovered a linen burial cloth used during Egypt's Middle Kingdom some 4000 years ago. Careful analysis shows that the cloth contains 80% of the ^{14}{\rm C} that it is estimated to have originally contained. How old is the cloth?

the cloth is old by 1,844 years

Explanation:

The computation is shown below:

The half-life of C^(14) is 5730 years

Now

=1.210 × 10^-4 years^(-1)

Now

= .000121,

so t = 1844 yrs

hence, the cloth is old by 1,844 years

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.