Physics, 17.07.2019 05:10 lilrariwmb23701

Aball is thrown horizontally from the top of a building 0.10 km high. the ball strikes the ground at a point 65 m horizontally away from and below the point of release. what is the speed of the ball just before it strikes the ground?

Answers: 1

Show answers

Answers

Answer from: ericlawton

The speed of the ball just before it strikes the ground is equal to 46.55 m/s.

Given the following data:

Horizontal distance = 65 metersHeight of building = 0.10 km = 100 meters

We know that the acceleration due to gravity (g) of an object on planet Earth is equal to 9.8 m/s^2 .

To determine the speed of the ball just before it strikes the ground:

First of all, we would determine the time it took the ball to strike the ground by using the formula for maximum height.

$H = \frac{1}{2} gt^2\\\\100 = \frac{1}{2} \times 9.8 \times t^2\\\\200 = 9.8t^2\\\\t^2 = \frac{200}{9.8} \\\\t^2=20.41\\\\t=\sqrt{20.41}$

Time, t = 4.52 seconds

Next, we would find the horizontal velocity:

$Horizontal\;velocity = \frac{horizontal\;distance}{time} \\\\Horizontal\;velocity = \frac{65}{4.52}$

Horizontal velocity, V1 = 14.38 m/s

Also, we would find the velocity of the ball in the horizontal direction:

$V_2^2 = U^2 + 2aS\\\\V_2^2 = 0^2 + 2(9.8)(100)\\\\V_2^2 = 1960\\\\V_2 = \sqrt{1960} \\\\V_2 = 44.27 \;m/s$

Now, we would calculate the speed of the ball just before it strikes the ground by finding the resultant speed:

$V = \sqrt{V_1^2 + V_2^2} \\\\V = \sqrt{14.38^2 + 44.27^2}\\\\V = \sqrt{206.7844‬ + 1959.8329‬}\\\\V =\sqrt{2166.6173}$

Speed, V = 46.55 m/s

Read more: link

Answer from: laurentsupreme

v = 46.55 m/s

Explanation:

It is given that,

A ball is thrown horizontally from the top of a building 0.10 km high, d = 0.1 km = 100 m

The ball strikes the ground at a point 65 m horizontally away from and below the point of release, h = 65 m

At maximum height, velocity of the ball is 0. So, using the equation of motion as :

$d=ut+\dfrac{1}{2}at^2$

Here, a = g

$100=0+\dfrac{1}{2}\times 9.8t^2$

$t=4.51\ s$

Let v_x is the horizontal velocity of the ball. It is calculated as :

$v_x=\dfrac{65\ m}{4.51\ s}=14.41\ m/s$

Let v_y is the final speed of the ball in y direction. It can be calculated as :

v_y^2+u_y^2=2as

u_y=0

v_y^2=2gd

$v_y^2=2\times 9.8\times 100$

$v_y=44.27\ m/s$

Let v is the speed of the ball just before it strikes the ground. It is given by :

$v=\sqrt{v_x^2+v_y^2}$

$v=\sqrt{14.41^2+44.27^2}$

v = 46.55 m/s

So, the speed of the ball just before it strikes the ground is 46.55 m/s. Hence, this is the required solution.

Answer from: Quest

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.

Answer from: Quest

show the wavelengths of a wave. show the crests of a wave.

Another question on Physics

Physics, 21.06.2019 21:30

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Answers: 3

Answer

Physics, 22.06.2019 07:50

Calculate the ratio of h+ ions to oh– ions at a ph = 6. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 6. are they the same? why or why not? record your explanation in table a. what is the concentration of h+ ions at a ph = 6? mol/l what is the concentration of oh– ions at a ph = 6? mol/l what is the ratio of h+ ions to oh– ions at a ph = 6? : 1

Answers: 1

Answer

Physics, 22.06.2019 14:30

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?

Answers: 1

Answer

Physics, 22.06.2019 15:30

What is the increase in density of a medium due to wave travel?

Answers: 2

Answer

You know the right answer?

Aball is thrown horizontally from the top of a building 0.10 km high. the ball strikes the ground at...