You need to figure out how high it is from the 3rd floor of keck science building to the ground. you know that the distance from the ground to the 2nd floor is 5m. your friend drops a ball from rest from the 3 rd floor and you start to time the ball when it passes by you at the 2nd floor. you stop the timer when the ball hits the ground. the time recorded is 0.58 seconds.

1.624 m

Explanation:

Given

height of 2nd floor =5 m

time recorded is 0.58 sec

Let h be the height of third floor above 2 nd floor

here u=0

t=time taken to cover height h

  ----------1

Now time taken to complete whole building length

 ----------2

Subtract 1 form 2

Taking gravity

1=(2t+0.58)(0.58)

t=0.57 s

Substitute the value of t in 1

h=1.624 m

i am single too don't feel bad

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards