why is the following situation impossible? a normally proportioned adult walk briskly along a straight line in the +x direction, standing straight up and holding his right arm vertical and next to his body so that the arm does not swing. his right hand holds a ball at his side a distance h above the floor. when the ball passes above a point marked as x=0 on the horizontal floor, he opens his fingers to release the ball from rest relative to his hand. the ball strikes the ground for the first time at position x= 7.00 h.
yes, possible, given he and the ball had in initial velocity.
Time it takes to fall h meters:
h=1/2 g t^2
t=sqrt (2h/g)
velocity intial= distance/time= 7h/sqrt(2h/g)=
velocity initial= 1/sqrt(2/hg)
so if h initial= 1meter, then velocity
is 7/sqrt(1/4.9)= 7sqrt(4.9)= about 15m/s which is a really brisk walk. I cant run half that fast.
Aplastic walk his two sides that measures 4 cm, 2 can, and 3 cm. it's mass is 19.2 g. Predict the block will float in water. Will it float in all of oil? Gather information before making a production.
To understand why the situation described is impossible, let's break it down step by step:
1. A normally proportioned adult walks briskly along a straight line in the +x direction - This means the person is moving forward in a straight line.
2. The adult is standing straight up and holding his right arm vertical and next to his body so that the arm does not swing - This implies that the person's arm remains stationary and does not move as they walk.
3. The right hand holds a ball at his side a distance h above the floor - The person is carrying a ball at a specific height (h) above the ground.
4. When the ball passes above a point marked as x=0 on the horizontal floor, he opens his fingers to release the ball from rest relative to his hand - At a certain point (x=0), the person opens their fingers and releases the ball. The ball starts falling.
5. The ball strikes the ground for the first time at position x=7.00h - The ball hits the ground at a position that is 7 times the initial height (7.00h).
Now, let's analyze the situation:
When the person releases the ball, it will initially have both vertical and horizontal components of velocity. The vertical component will be responsible for the ball's descent, while the horizontal component will contribute to its forward motion because the person is walking in the +x direction.
However, since the person's arm is held vertically without swinging, there is no initial horizontal velocity imparted to the ball. Therefore, there is no horizontal force acting on the ball after its release, and it will only have a vertical downward force due to gravity.
As a result, the ball will follow a parabolic path determined solely by the force of gravity, falling straight down without any forward motion. This means the ball cannot strike the ground at a position (x) that is 7.00 times its initial height (h) away from the release point.
Therefore, the situation described is impossible based on the assumption that the person's arm does not swing, which would provide the initial horizontal velocity required for the ball to travel horizontally while falling.