Aperson is standing on top of a cliff and falls down. if he takes 3.7 s to hit the ground, how high up is the cliff?

h = 67.081 m

Explanation:

Given that,

The time taken by a person to fall down is, t = 2.2 s

The height of the cliff from the ground, h = ?

The distance that the person will fall through the time is given by the formula

                               S = 1/2 gt²  m

Where,        

                             g - acceleration due to gravity

Substituting the values in the above equation

                              S = 1/2 x 9.8 m/s² x (3.7 s)²

                                 = 67.081  m

Therefore, the height of the cliff from the ground is, h = 67.081  m

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.