What type of research based on approach that used to describe variables rather than to test a predicted relationship between variables?

Answer:

(a) The kinetic energy of the bowling ball just before it hits the matress is 102.974 joules.

(b) The work done by the gravitational force of Earth on bowling ball during the first part of the fall is 102.974 joules.

(c) Work done by gravitational force on bowling ball when mattress is compressed is 10.298 joules.

(d) The work done by the mattress on the bowling ball is 113.272 joules.

Explanation:

The statement is incomplete. The complete question is:

In a mattress test, you drop a 7.0 kg bowling ball from a height of 1.5 m above a mattress, which as a result compresses 15 cm as the ball comes to a stop.

(a) What is the kinetic energy of the ball just before it hits the mattress?  

(b) How much work does the gravitational force of the earth do on the ball as it falls, for the first part of the fall (from the moment you drop it to just before it hits the mattress)?  

(c) How much work does the gravitational force do on the ball while it is compressing the mattress?

(d) How much work does the mattress do on the ball? (You’ll need to use the results of parts (a) and (c)）

(a) Based on the Principle of Energy Conservation, we know that ball-earth system is conservative, so that kinetic energy is increased at the expense of gravitational potential energy as ball falls:

[tex]K_{1}+U_{g,1} = K_{2}+U_{g,2}[/tex] (Eq. 1)

Where:

[tex]K_{1}[/tex], [tex]K_{2}[/tex] - Kinetic energies at top and bottom, measured in joules.

[tex]U_{g,1}[/tex], [tex]U_{g,2}[/tex] - Gravitational potential energies at top and bottom, measured in joules.

Now we expand the expression by definition of gravitational potential energy:

[tex]U_{g,1}-U_{g,2} = K_{2}-K_{1}[/tex]

[tex]K_{2}= m\cdot g \cdot (z_{1}-z_{2})+K_{1}[/tex] (Eq. 1b)

Where:

[tex]m[/tex] - Mass of the bowling ball, measured in kilograms.

[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.

[tex]z_{1}[/tex], [tex]z_{2}[/tex] - Initial and final heights of the bowling ball, measured in meters.

If we know that [tex]m = 7\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{1}= 1.5\,m[/tex], [tex]z_{2} = 0\,m[/tex] and [tex]K_{1} = 0\,J[/tex], the kinetic energy of the ball just before it hits the matress:

[tex]K_{2} = (7\,kg)\cdot \left(9.807\,\frac{m}{s^{2}}\right)\cdot (1.5\,m-0\,m)+0\,m[/tex]

[tex]K_{2} = 102.974\,J[/tex]

The kinetic energy of the bowling ball just before it hits the matress is 102.974 joules.

(b) The gravitational work done by the gravitational force of Earth ([tex]\Delta W[/tex]), measured in joules, is obtained by Work-Energy Theorem and definition of gravitational potential energy:

[tex]\Delta W = U_{g,1}-U_{g,2}[/tex]

[tex]\Delta W = m\cdot g\cdot (z_{1}-z_{2})[/tex] (Eq. 2)

If we know that [tex]m = 7\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{1}= 1.5\,m[/tex] and [tex]z_{2} = 0\,m[/tex], then the gravitational work done is:

[tex]\Delta W = (7\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (1.5\,m-0\,m)[/tex]

[tex]\Delta W = 102.974\,J[/tex]

The work done by the gravitational force of Earth on bowling ball during the first part of the fall is 102.974 joules.

(c) The work done by the gravitational force of Earth while the bowling when mattress is compressed is determined by Work-Energy Theorem and definition of gravitational potential energy:

[tex]\Delta W = U_{g,2}-U_{g,3}[/tex]

Where [tex]U_{g,3}[/tex] is the gravitational potential energy of the bowling ball when mattress in compressed, measured in joules.

[tex]\Delta W = m\cdot g \cdot (z_{2}-z_{3})[/tex]

Where [tex]z_{3}[/tex] is the height of the ball when mattress is compressed, measured in meters.

If we know that [tex]m = 7\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{2}= 0\,m[/tex] and [tex]z_{3} = -0.15\,m[/tex], the work done is:

[tex]\Delta W = (7\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot [0\,m-(-0.15\,m)][/tex]

[tex]\Delta W = 10.298\,J[/tex]

Work done by gravitational force on bowling ball when mattress is compressed is 10.298 joules.

(d) The work done by the mattress on the ball equals the sum of kinetic energy just before mattress compression and the work done by the gravitational force when mattress is compressed:

[tex]\Delta W' = K_{2}+\Delta W[/tex]

([tex]K_{2} = 102.974\,J[/tex], [tex]\Delta W = 10.298\,W[/tex])

[tex]\Delta W' = 113.272\,J[/tex]

The work done by the mattress on the bowling ball is 113.272 joules.

Answer:

(1,)

Explanation:

Answer:

magnitude: 21.6; direction: 33.7°

Explanation:

Answer:

Platelets

Explanation:

Platelets are tiny blood cells that help your body form clots to stop bleeding. If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a clot to stop the bleeding.

Answer:

[tex]\boxed {\tt Platelets}[/tex]

Explanation:

There are three main types of blood cells:

We are looking for which blood cell helps clot the blood. From the list above, we can see the best answer is platelets.

Answer:

B. 450 N

Explanation:

Use Hooke's law:

F = kx

150 N = k (1 m)

k = 150 N/m

F = kx

F = (150 N/m) (3 m)

F = 450 N

Answer:

168

Explanation:

Answer: a 15 kg object would weigh the most on Neptune

168 N

Answer:

v = 66 m/s

Explanation:

Given that,

The initial velocity of a car, u = 0

Acceleration of the car, a = 11 m/s²

We need to find the final velocity of the toy after 6 seconds.

Let v is the final velocity. It can be calculated using first equation of motion. It is given by :

v = u +at

v = 0 + 11 m/s² × 6 s

v = 66 m/s

So, the final velocity of the car is 66 m/s.

Answer:

I think it will get colder

Explanation:

Answer:

The water molecules go faster as it gets colder they go slower

Explanation:

trust me thats the answer

Answer:

35.35 m

Explanation:

The following data were obtained from the question:

Initial velocity (u) = 20 m/s

Angle of projection (θ) = 30°

Acceleration due to gravity (g) = 9.8 m/s²

Range (R) =.?

The range (i.e how far away) of the ball can be obtained as follow:

R = u² Sine 2θ /g

R = 20² Sine (2×30) / 9.8

R = 400 Sine 60 / 9.8

R = (400 × 0866) / 9.8

R = 346.4 / 9.8

R = 35.35 m

Therefore, the range (i.e how far away) of the ball is 35.35 m

Answer:

Average speed

Explanation:

250/50=5

1000/20=5

Answer:

[tex]E_s = 277.13V[/tex]

Explanation:

Given

[tex]Load\ Voltage = 480V[/tex]

Required

Determine the voltage dropped in each stage.

The relation between the load voltage and the voltage dropped in each stage is

[tex]E_l = E_s * \sqrt3[/tex]

Where

[tex]E_l = 480[/tex]

So, we have:

[tex]480 = E_s * \sqrt3[/tex]

Solve for [tex]E_s[/tex]

[tex]E_s = \frac{480}{\sqrt3}[/tex]

[tex]E_s = \frac{480}{1.73205080757}[/tex]

[tex]E_s = 277.128129211[/tex]

[tex]E_s = 277.13V[/tex]

Hence;

The voltage dropped at each phase is approximately 277.13V

Answer:

1.25 g/cm^3

Explanation:

mass-30.0g

volume- 4cm×2cm×3cm=24cm^3

density?

*to find density

Density=Mass/Volume

=30÷24

=1.25g/cm^3

Answer:

(a). The kinetic friction force is 1950 N.

(b). The magnitude of force will be equal of friction force

Explanation:

Given that,

Constant speed = 6.38 m/s

Force [tex]F=7.50\times10^{3}\ N[/tex]

Kinetic friction = 0.26

(a). We need to calculate the friction force

Using formula of friction force

[tex]f_{k}=\mu F_{N}[/tex]

Put the value into the formula

[tex]f_{k}=0.26\times7.50\times10^{3}[/tex]

[tex]f_{k}=1950\ N[/tex]

(b). If the only other horizontal force exerted on the sleigh is due to the horses pulling the sleigh,

We need to calculate the magnitude of this force

According to given data,

The same force will be applied to keep constant velocity.

Hence, (a). The kinetic friction force is 1950 N.

(b). The magnitude of force will be equal of friction force.

(a). The kinetic friction force is 1950 N.

(b). The magnitude of force will be equal of friction force

a. The magnitude of the kinetic friction force experienced by the sleigh is

[tex]= 0.76 \times 7.50 \times 10^3[/tex]

= 1950 N

b. It should be equivalent to the friction force.

Learn more: https://brainly.com/question/24908711?referrer=searchResults

Answer:

Total energy = Kinetic Energy + Potential Energy = Constant

Since the potential energy is lowest at point D the kinetic energy will be greatest at point D and the velocity will be the greatest.

Answer:

Covalent Bond

Explanation:

i took the test , mark me brainliest.

Answer: Electrical

Explanation: Atoms are tied together by electrical bonding forces.

Answer:

During a phase change, a substance undergoes transition to a higher energy state when heat is added, or to a lower energy state when heat is removed. Heat is added to a substance during melting and vaporization. Latent heat is released by a substance during condensation and freezing. Explanation:

An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still loosely gravitationally bound to each other. In contrast, globular clusters are very tightly bound by gravity. ... Open clusters are very important objects in the study of stellar evolution.

Answer: D 160kg object moving 126 m/s

Explanation:

An object having a mass of 162 kg and moving with a velocity of 124 m/sec will require the greatest amount of force to change its motion. The correct option is D.

Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.

If the object has to stop, the final velocity must be zero. If the time is constant, the amount of force only depends on the mass and the velocity at which the body is moving.

The amount of force on the object depends on the momentum of the body.

The momentum of the body is;

P = mv

Object D will require the greatest amount of force to change its motion. Because the momentum of the body for option D is the greatest.

Hence, the correct option is D.

Learn more about the Force, here;

https://brainly.com/question/26115859

#SPJ2

Answer:

The  value of the power is   [tex]P_c  =  38.55 \  W [/tex]

Explanation:

From the question we are told that

   The  power  rating [tex]P_{1000} =P_b=  52 \  W[/tex]

    The frequency is  [tex]f = 1000 \  Hz[/tex]

    The  frequency at which the sound intensity decreases  [tex]f_k  =  20 \  Hz[/tex]

     The decrease in intensity is by [tex]\beta  =  1.3 dB[/tex]

Generally the  initial intensity of the speaker  is mathematically represented as

     [tex]\beta_1 =  10 log_{10} [\frac{P_b}{P_a} ][/tex]

Generally the intensity of the speaker after it has been decreased is

       [tex]\beta_2 =  10 log_{10} [\frac{P_c}{P_a} ][/tex]

So

[tex]\beta_1-\beta_2 =  10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ][/tex]

=>  [tex]\beta =  10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ]= 1.3[/tex]

=>  [tex]\beta =10log_{10} [\frac{\frac{P_b}{P_a}}{\frac{P_c}{P_a}} ] = 1.3[/tex]

=>  [tex]\beta =10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]

=> [tex]10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]

=> [tex]log_{10} [\frac{P_b}{P_c} ] = 0.13[/tex]

taking atilog of both sides

[tex][\frac{P_b}{P_c} ] = 10^{0.13}[/tex]      

=>[tex][\frac{52}{P_c} ] = 10^{0.13}[/tex]      

=>  [tex]P_c  =  \frac{52}{1.34896}[/tex]

=>   [tex]P_c  =  38.55 \  W [/tex]

Answer:

1- t^3

2- t^2

3- t1

Explanation:

The acceleration produced in a body, while travelling in a circular motion, due to change in direction of motion is called centripetal acceleration. The formula of the centripetal acceleration is as follows:

ac = v²/r

where,

ac = centripetal acceleration

v = speed

r = radius

for a constant radius the centripetal acceleration will be directly proportional to the speed of object. The speed of pendulum will be lowest at t1 due to zero speed initially. Then the speed will increase gradually having greater speed at t^2 and the highest speed and centripetal acceleration at t^3. Therefore, the three instants in tie can be written in following order from greatest centripetal acceleration to lowest:

1- t^3

2- t^2

3- t1

Answer:

The one with the faster velocity is the one with a velocity of -10m/s

Answer:

The two charged objects will exert equal and opposite forces on each other.

Explanation:

Coulomb's law states that the electrical force between two charged objects is directly proportional to the product of charges on the objects and inversely proportional to the square of the distance between the two objects.

This force of attraction or repulsion between the two charged objects is always equal and opposite.

Therefore, the two charged objects will exert equal and opposite forces on each other.

Answer:

2nd option on edge2021

Explanation:

Explanation:

When sound travels in a given "medium", it would touch the surface of another "medium" and will bounce back in some other direction, this occurrence is called the reflection of sound.