Question

Objects that are thrown upwards as they gain height their speed goes: a. Increasing

b. Staying the same
c. Decreasing
d. Duplicating the initial

Answer 1

The correct option is 'c': Decreases.

Step-by-step explanation:

As we know that when we throw a ball upwards we imoart a kinetic energy to the bsll. As the ball moves upwards the kinetic energy of the ball starts to decrease as the ball slows down as it moves upwards as work has to be done for movement against gravity. This work done against gravity is stored as potential energy of the ball.

Mathematically as we throw the ball upward's with velocity 'u' it's initial kinetic energy equals
`E_(initial)=(1)/(2)mu^(2)`

As the ball attain's a height 'h' it's total energy is sum of the potential and the remaining kinetic energy as follows

`E(h)=mgh+(1)/(2)mv^(2)`

Equating both the energies we get

`(1)/(2)mu^(2)=mgh+(1)/(2)mv^(2)\\\\\\therefore v=\sqrt{u^(2)-2gh}`

Hence we can see as the height increases the velocity decreases.