Do the following calculation and express the final answer in

Susan's 10.0kg baby brother Paul sits on a mat. Susan pulls the mat across the floor using a rope that is angled 30? above the f

elena-s [515]

Answer:

The speed after being pulled is 2.4123m/s

Explanation:

The work realize by the tension and the friction is equal to the change in the kinetic energy, so:

$W_T+W_F=K_f-K_i$ (1)

Where:

$W_T=T*x*cos(0)=32N*3.2m*cos(30)=88.6810J\\W_F=F_r*x*cos(180)=-0.190*mg*x =-0.190*10kg*9.8m/s^{2}*3.2m=59.584J\\ K_i=0\\K_f=\frac{1}{2}*m*v_f^{2}=5v_f^{2}$

Because the work made by any force is equal to the multiplication of the force, the displacement and the cosine of the angle between them.

Additionally, the kinetic energy is equal to $\frac{1}{2}mv^{2}$ , so if the initial velocity $v_i$ is equal to zero, the initial kinetic energy $K_i$ is equal to zero.

Then, replacing the values on the equation and solving for $v_f$ , we get:

$W_T+W_F=K_f-K_i\\88.6810-59.5840=5v_f^{2}\\29.097=5v_f^{2}$

$\frac{29.097}{5}=v_f^{2}\\\sqrt{5.8194}=v_f\\2.4123=v_f$

So, the speed after being pulled 3.2m is 2.4123 m/s

8 0

3 years ago

Which of the following is a TRUE

DENIUS [597]

The statement that is the most true regarding the states of matter is the first statement.

A. Most matter on Earth exists as a solid, liquid, or gas.

This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.

Therefore, B is incorrect.

C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.

D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.

7 0

3 years ago

☆ Correct and rewrite the following statements:

kvv77 [185]

Answer:

<h3>e)</h3><h3>Question:-</h3>

Electroplating is based on magnetic effect of electricity.

<h3>Answer:-</h3>

It's incorrect sentence 
As we know that, while electroplating there are two rods, one becoming cathode and another one becoming anode. During electroplating, when electricity is given through the rods, the anode produces positive ions which gets received at the cathode rod and negative ions produced at cathode collects at anode rod which results to the plating of the desired substance. Here, it is a chemical effect of electricity resulting to plating.

So correct sentence is:

Electroplating is based of chemical effect of electricity.

<h3>f)</h3><h3>Question:-</h3>

An electric bulb glows due to the chemical effect of electricity.

<h3>Answer:-</h3>

It's incorrect sentence 
As we know that, in an electric bulb there is a filament. When electricity is given in that filament of the electric bulb, the filament gets intensely heated up and results to the emission of light. Due to this heating of the filament due to electricity the electric bulb glows.

So correct sentence is:

An electric bulb glows due to the heating effect of electricity.

6 0

2 years ago

I need this asap pls

user100 [1]

Answer:

2 i think

Explanation:

3 0

3 years ago

Rotation of the lever OA is controlled by the motion of the contacting circular disk of radius r = 300 mm whose center is given

sergiy2304 [10]

Answer:

The angular velocity is

5.64rad/s

Explanation:

This problem bothers on curvilinear motion

The angular velocity is defined as the rate of change of angular displacement it is expressed in rad/s

We know that the velocity v is given as

v= ωr

Where ω is the angular velocity

r is 300mm to meter = 0.3m

the radius of the circle

described by the level

v=1.64m/s

Making ω subject of the formula and solving we have

ω=v/r

ω=1.64/0.3

ω=5.46 rad/s

3 0

3 years ago