Aball is thrown horizontally from a height of 19 m and hits the ground with a speed that is five times its initial speed. what is the initial speed?

The initial speed of the ball is 3.93 m/s.

Explanation:

It is given that,

A ball is thrown horizontally from a height of 19 m, h = 19 m

Let u is the initial speed of the ball so, its final velocity, v = 5u

Using third equation of motion as :

u = 3.93 m/s

So, the initial speed of the ball is 3.93 m/s. Hence, this is the required solution.

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.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).