A small first-aid kit is dropped by a rock climber who is descending steadily at -1.25 m/s. After 2.5 seconds, what is the velocity of the first aid kit and how far is the kit below the climber?

Answer:

(a) h = 5.1 m

(b) v = 14.13 m/s

Explanation:

(a)

We will use the law of conservation of energy. For this situation it states that:

Loss in Potential Energy of Sphere = Gain in Kinetic Energy of the Sphere

mgh = (1/2)mv²

h = v²/2g   --------------- equation (1)

where,

h = height = ?

v = speed at lowest point = 10 m/s

g = 9.8 m/s²

Therefore,

h = (10 m/s)²/(2)(9.8 m/s²)

h = 5.1 m

(b)

using the equation (1)

h = v²/2g

v = √2gh

where,

v = velocity = ?

g = 9.8 m/s²

h = height = 2(5.1 m) = 10.2 m

Therefore,

v = √[2(9.8 m/s²)(10.2 m)]

v = 14.13 m/s

The height from which the sphere was released is 5.1 m

When the height is doubled, the speed of the sphere becomes 14.14 m/s.

The given parameters:

The height from which the sphere was released is calculated as follows;

[tex]P.E = K.E\\\\mgh = \frac{1}{2}mv^2\\\\gh = \frac{1}{2}v^2\\\\h = \frac{v^2}{2g}\\\\h = \frac{(10)^2}{2(9.8)} \\\\h = 5.1 \ m[/tex]

When the height is doubled, the speed of the sphere becomes;

[tex]h = \frac{v^2}{2g} \\\\v^2 = 2gh\\\\v = \sqrt{2gh} \\\\v = \sqrt{2 \times 9.8 \times (2 \times 5.1)} \\\\v = 14.14 \ m/s[/tex]

Learn more about  conservation of mechanical energy here: https://brainly.com/question/6852965

Answer:

0.26

Explanation:

Given that :

Diameter of ball = 3.81 cm = 3.81/100 = 0.0381 m

Radius (r) = 0.0381 / 2 = 0.01905 m

Average density of ball (Db) = 0.0842 g/cm³ = (0.0842 / 1000)kg / 10^-6 = 0.0842/ 1000 * 10^6 = 84.2kg/m³

Density of water (Dw) = 1000kg/m³

Volume of hollow ball: (4/3) * pi * r³

V = (4/3) * π * 0.01905^3

V = 0.0000289583 m³

Required force = (Dw * V * g) - (Db * V * g)

= (1000 * 0.0000289583 * 9.8) - (84.2 * 0.0000289583 * 9.8)

= 0.259896109172

= 0.2598 N

To determine the force that must be applied to the hollow ball to hold it stationary while it is completely submerged under water is 0.2243 Newton.

Given the following data:

Density of water = 1000 [tex]kg/m^3[/tex]

Conversion:

Diameter of hollow ball = 3.81 centimeters to meters = [tex]\frac{3.81}{100} = 0.0381\;m[/tex]

Density of hollow ball = 0.0842 [tex]g/cm^3[/tex] to [tex]kg/m^3[/tex] = [tex]\frac{0.0842 \times 10^6}{1000} = 84.2 \;kg/m^3[/tex]

To determine the force that must be applied to the hollow ball to hold it stationary while it is completely submerged under water:

First of all, we would calculate the volume of the hollow ball by using the formula:

[tex]Volume = \frac{4}{3} \pi r^3\\\\Volume = \frac{4}{3} \times 3.142 \times 0.01905^3\\\\Volume = 4.19 \times 0.0000069\\\\Volume = 0.000029 \;m^3[/tex]

Next, we would find the force required for water and the hollow ball:

For water:

[tex]F_w = D_wVg\\\\F_w = 1000 \times 0.000029 \times 9.8\\\\F_w = 0.2842\; Newton[/tex]

For hollow ball:

[tex]F_h = D_hVg\\\\F_h = 84.2 \times 0.000029 \times 9.8\\\\F_h = 0.0239\; Newton[/tex]

Now, we can find the force that must be applied to the hollow ball:

[tex]Force = F_w - F_h\\\\Force = 0.2482 - 0.0239[/tex]

Force = 0.2243 Newton

Read more: https://brainly.com/question/18320053

Answer:

Cohesion

Explanation:

Surface tension of water refers to the ability of the surface of water as a liquid to resist an external force. Surface tension of a liquid like water is dependent on the force of attraction that hold its molecules to one another, which is a force called COHESIVE FORCE.

Cohesion is a property of water characterized by the ability of water molecules to be attracted to one another. This cohesive property causes its molecules to be able to resist external forces or in other words is responsible for the SURFACE TENSION. Hence, the stronger the cohesive force between molecules of a liquid, the higher the surface tension.

Answer:

The car will take 5 seconds

Explanation:

Constant Acceleration Motion

It's a type of motion in which the velocity of an object changes uniformly in time.

If the object starts from a speed vo during a time t with an acceleration a, then its final speed is:

[tex]v_f=v_o+at[/tex]

The car is accelerating at a rate of a= 4~m/s^2 and reaches a speed of vf=20 m/s starting from rest (vo=0).

From the equation shown above, we solve for t:

[tex]\displaystyle t=\frac{v_f-v_o}{a}[/tex]

[tex]\displaystyle t=\frac{20-0}{4}[/tex]

[tex]\displaystyle t=\frac{20}{4}[/tex]

t = 5 seconds

The car will take 5 seconds

Answer:

The correct answer is B

normal force=mass*gravitational force

normal force=40*0

normal force=40

Answer:

1200

Explanation:

Answer:

[tex]\huge\boxed{\sf T = 2.04\ secs}[/tex]

Explanation:

Given Data:

Initial Velocity = [tex]\sf V_{i}[/tex] = 20 m/s

Angle = [tex]\sf \theta[/tex] = 30°

Acceleration due to gravity = g = 9.8 m/s²

Required:

Time of flight = T = ?

Formula:

[tex]\sf T = \frac{2\ V_{i}\ sin\theta}{g}[/tex]

Solution:

Putting values in the above formula

T = 2(20)sin 30 / 9.8

T = 40 (0.5) / 9.8

T = 20 / 9.8

T = 2.04 secs

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Heavy objects fall at the same rate (or speed) as light ones. The acceleration due to gravity is about 10 m/s2 everywhere around earth, so all objects experience the same acceleration when they fall.

Explanation:

Answer:

The average speed of an object is defined as the distance traveled divided by the time elapsed. Velocity is a vector quantity, and average velocity can be defined as the displacement divided by the time.

Answer: True

Explanation: I got it right on my test :)

Answer:

2.46

Explanation:

From the question given above, the following data were obtained:

Critical angle (C) = 24 °

Refractive index (n) =?

The refractive index of the diamond can be obtained by using the following formula as illustrated below:

Refractive index (n) = 1 / sine [critical angle (C)]

n = 1/sine C

n = 1 / sine 24 °

n = 1/0.4067

n = 2.46

Thus, the refractive index of the diamond is 2.46

Answer:  71.43 kilograms

This value is approximate rounded to two decimal places.

=====================================================

Explanation:

The ground is pushing up with a normal force of 700 N. Because the box is sitting still, this means the force of gravity is pulling the box down with a force of 700N to keep things balanced.

If the force of gravity was greater than 700N, then the box would fall through the ground. If the force of gravity was smaller than 700N, then the box would be accelerated upward. Since neither event is happening, the force of gravity must be equal to the normal force.

Now turn to Newton's second law which says

F = ma

where F is the force, m is the mass and 'a' is the acceleration. We're given the acceleration of gravity is roughly 9.80 m/s^2. So a = 9.80

The force we'll plug in is F = 700. The value of m is unknown, but we can solve for it as such

F = ma

700 = m*9.80

700 = 9.08m

9.80m = 700

m = 700/9.80

m = 71.4285714285714

m = 71.43

The mass is roughly 71.43 kilograms.

Answer:

wind has two important things that is direction and speed.

Answer:

Photosynthesis is the process of using water, carbon dioxide and sunlight to produce sugar. The process of photosynthesis requires specialized cellular structures called chloroplasts to capture energy from the Sun and converted into chemical energy.

Explanation:

Answer:

22 kg

Explanation:

I hope this helps!

Answer:

22 kilograms

Hope it helps :) (if it does can i pls have brainliy thing)

Answer:

The time it takes for the jet to reach landing speed is approximately 0.136 hours which is approximately 489 seconds

The landing speed is approximately 466.365 km/hr

Explanation:

The given parameters are;

The initial cruising speed of the jet = Mach 0.79 = 844 km/hr

The rate of speed reduction in the last 89 km = -2780 km/hr²

The distance it  takes the jet to reduce its speed for landing = 89 km

Given the above information,  we make use of the following equation of motion;

s = u·t - 1/2·a·t²

v² = u² - 2·a·s

Where;

s = The distance over which the acceleration (deceleration) is applied = 89 km

u = The initial velocity = 844 km/hr

t = The time taken for the accelerating/decelerating motion

v = The final velocity (landing speed)

Substituting the values gives;

v² = 844² - 2·(2780)·89 = 217496

v = √217496 = 466.365 km/hr

v ≈ 466.365 km/hr

Therefore, the landing speed, v  ≈ 466.365 km/hr

The time it takes is given by the equation, v = u - a·t

Therefore;

t = (u - v)/a = (844 - 466.365)/2780 ≈ 0.136 hours

The time it takes for the jet to reach landing speed ≈ 0.136 hours

From, s = u·t - 1/2·a·t², we have

89 = 844·t - 1/2 × 2780 × t²

89 = 844·t - 1390 × t²

1390 × t² - 844·t + 89 = 0

Solving with an online application gives;

t = 211/695 + (√(27187/2))/695 = 0.4715 hours or t = 211/695 - (√(27187/2))/695 = 0.136 hours

We note that the second time is for the time it will take the jet to get back to 89 km after reaching a speed of 0

Therefore, the correct time is t = 0.136 hours

The time it takes for the jet to reach landing speed ≈ 0.136 hours

Answer:

thats a lot, which one u want me to do?

Explanation:

Answer:

you can use a balance

Explanation:

when you tend to measure something you are using your brain so why dont you use your brain dimwitt

Answer:

I think it a

Explanation:

Answer:

c

Explanation:

Answer:

what?

Explanation:

Answer:

the graph represents an endothermic reaction

Explanation:

remember:

endo- inside

exo- out

Answer:

D

Explanation:

because all are reffering to the answer you need

Answer:

C is corret answer okay

Answer:

once a week

Explanation:

once a week so answer B

Answer:

B-Once a week

Explanation:

You answer is B-Once a week

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 6500 × 0.3

We have the final answer as

Hope this helps you

Answer:

The answer are B

Explanation:the two samples haves yellow color :)

Answer:

B or 2

Explanation:

both of the samples contain a yellow color.