Hi gir_ls join nkd-mbja-nuj

A ball, which has a mass of 1.25 kg, is thrown straight up from the top of a building 225 meters tall with a velocity of 52.0 m/

Anastasy [175]

First we will find the speed of the ball just before it will hit the floor

so in order to find the speed of the cart we will first use energy conservation

$KE_i + PE_i = KE_f + PE_f$

$\frac{1}{2}mv_i^2 + mgh = \frac{1}{2}mv_f^2 + 0$

$\frac{1}{2}(1.25)(52)^2 + 1.25(9.8)(225) = \frac{1}{2}(1.25)v_f^2$

So by solving above equation we will have

$v_f = 84.3 m/s$

now in order to find the momentum we can use

$P = mv$

$P = 1.25 \times 84.3$

$P = 105.4 kg m/s$

3 0

3 years ago

A car takes 15 minutes to travel along a road that is 20 km long.

iogann1982 [59]

Answer:

C

Explanation:

15. 20

x4. x4

60. 80

80km/h

8 0

3 years ago

Read 2 more answers

In a 49 s interval, 595 hailstones strike a glass window of an area of 0.954 m at an angle of 25° to the window surface. Each ha

eduard

Average force on the window: 0.32 N

Explanation:

The average force exerted on the window is given by Newton's second law

$F=\frac{\Delta p}{\Delta t}$

where

$\Delta p$ is the net change in momentum of the hailstones in a time interval of $\Delta t$

In order to find the change in momentum, we have to consider only the component of the hailstone's momentum perpendicular to the window, therefore:

$p_i =m u sin \theta$ is the initial momentum of one hailstone, with

m = 7 g = 0.007 kg is the mass

$u=4.5 m/s$ is the initial speed

$\theta=25^{\circ}$ is the angle with the window

The final momentum is

$p_f = mv sin \theta$

where

v = 4.5 m/s is the final speed (the collision is elastic so the speed is equal, while the direction changes)

$\theta=-25^{\circ}$ (after the rebound, the direction has changed)

So the change in momentum of 1 hailstone is

$\Delta p = mv sin(-25^{\circ})-mu sin(25^{\circ})=-2mu sin(25^{\circ})=-0.0266 kg m/s$

We are interested only in the magnitude, so

$\Delta p = 0.0266 kg m/s$

There are 595 hailstones hitting the window in 49 s, so the total change in momentum is

$\Delta p = 595\cdot 0.0266 = 15.8 kg m/s$

And therefore, the average force on the window is

$F=\frac{\Delta p}{\Delta t}=\frac{15.8}{49}=0.32 N$

Learn more about force:

brainly.com/question/8459017

brainly.com/question/11292757

brainly.com/question/12978926

#LearnwithBrainly

3 0

3 years ago

2. A solution that contains a small amount of salt and a large amount of water is said to be a _______ solution.

koban [17]

2. A dilute solution means that the amount of solvent (water, for this particular case) is significantly larger than the solute (salt). Thus, the answer is D. 6. John Dalton's atomic theory states that matter is made up of tiny indestructible objects called matter. The theory also indicates that although same elements have the same atoms, each element have unique set atoms that deinfe them. From this, we can conclude that the wrong assumption is C. 9. Atoms, by default, are electrically neutral. When an atom loses or gains electron/s, then they become ionized atoms or commonly called as ions. Thus, ionized atoms imply unequal number of protons and electrons. This means the answer must be A. 11. Analgesics are commonly used to relieve pain. Thus, the answer is C. 14. Adding up the atomic mass of the individual atoms will give you the molar mass of a compound. Therefore, the answer is B.: 15. The pH scale provides us the alkalinity or acidity of a solution based on the value. A value between 0 to 6 indicates that the solution is acidic. 7 is considered neutral and a value between 7 and 14 indicates that the solution is basic. Thus, the answer is D. 19. An element has consistent properties and can no longer be further identified into having individual properties. Thus, the answer is A. 20. The valence of an element dependeds on the number of electrons on the outermost shell. Thus, it is equal to the number of charge negative or positive charges on the ion. Hence, we have A<span>. :</span>

6 0

3 years ago

Read 2 more answers

What is velocity?<br>Please don't answer and let joinbrainly answer. Thank you.

Leokris [45]

Answer:

the speed of something in a given direction

Explanation:

mark me brainliest plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

7 0

2 years ago

Read 2 more answers

Hi gir_ls join nkd-mbja-nuj​

Hi gir_ls join nkd-mbja-nuj