If the ball shown in the figure lands in 0.5 s, about what height was it thrown from?

1.22 m

Explanation:

The equation of motion in this situation is:

(1)

Where:

is the final height of the ball

is the initial height of the ball

is the vertical component of the initial velocity (assuming the ball was thrown vertically and there is no horizontal velocity)

is the time at which the ball lands

is the acceleration due gravity

So, with these conditions the equation is rewritten as:

(2)

(3)

Finally:

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.