2) A four-legged wooden bar stool made out of solid Douglas fir (the Young's modulus is 1.0×1010N/m2) has legs that are 4.0 cm in diameter. When an 80 kg man sits on the stool, how much does the length of each of the legs decrease if the are 90 cm long? (Assume, for simplicity, that the stool's legs are vertical and that each bears the same load.)

measure their densities same density, same sub

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.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2