A 1-kilogram ball has 8 joules of kinetic energy.What is it speed?

On a frozen pond, a 8.54-kg sled is given a kick that imparts to it an initial speed of ð£0=1.87 m/s. The coefficient of kinetic

zhannawk [14.2K]

Answer:2.05 m

Explanation:

Given

Mass of sled $m=8.54 kg$

initial speed $u=0.187 m/s$

coefficient of kinetic Friction $\mu _k=0.087$

According to work-energy theorem work done by all the forces is change in Kinetic energy

$W_{friction}=\frac{1}{2}mv_i^2-\frac{1}{2}mv_f^2$

$\mu _kmg\times d=\frac{1}{2}\times 8.54\times 1.87^2$ ,where d= distance moved

$0.087\times 8.54\times 9.8\times d=14.93$

$d=\frac{14.93}{7.281}$

$d=2.05 m$

4 0

3 years ago

The way all jobs in modern society are connnected to other jobs is called

Contact [7]

The fact that all jobs in modern society are connected to other jobs is called division of labor.

<h3>What is division of labor?</h3>

We know that work is structured in such a way that jobs are connected. The jobs are split into smaller components and each person only does a small fragment of the that work that is to be done in a give case.

The fact that all jobs in modern society are connected to other jobs is called division of labor.

Learn more about division of labor:brainly.com/question/24691008

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6 0

2 years ago

After heavy rains, the floodplain of a river can deposit sediment. The newly deposited soil is nutrient rich and would be good A

AURORKA [14]

B. for growing vegetation and crops, because it says that, "The newly deposited soil nutrient rich and would be good." so it's good for the crops.

5 0

4 years ago

Read 2 more answers

If light energy to electric energy conversion using solar cells is 12 % efficient, how many square miles of land must be covered

umka2103 [35]

Complete Question

The light energy that falls on a square meter of ground over the course of a typical sunny day is about 20 MJ . The average rate of electric energy consumption in one house is 1.0 kW .

If light energy to electric energy conversion using solar cells is 12 % efficient, how many square miles of land must be covered with solar cells to supply the electrical energy for 350000 houses? Assume there is no cloud cover.

Answer:

The area is $A = 1.26 *10^{7} m^2$

Explanation:

From the question we are told that

The efficiency is $\eta =$ 12%

The number of houses is $N = 350000$

The light energy per day is $E = 20 \ MJ$

The average rating of electric energy for a house is $E_h = 1.0 \ k W = 1000W$

Generally the electric energy which the solar cells covering $1 \ m^2$ produces in a day is

$E_s = \eta * E$

$E_s = 0.12 * 20*10^{6}$

$E_s = 2.4 MJ m^{-2}$

Energy for required by one house for one day is

$E_H = E_h * 1 \ day$

$E_H = 1000 * 24 * 3600$

$E_H = 86.4 MJ$

Energy needed for 350000 house is

$E_z = 86.4 *10^{6} * 350000$

$E_z = 3.02 *10^{7} MJ$

The area covered is mathematically represented as

$A = \frac{3.02*10^{7} \ MJ}{2.4 \ MJ m^{-2}}$

$A = 1.26 *10^{7} m^2$

5 0

3 years ago

At the top of a cliff 100 m high, Raoul throws a rock upward with velocity 15 m/s. How much later should he drop a second rock f

Talja [164]

Answer:

d. 1.78s

Explanation:

The total time in the air for the second rock can be found with the next equation:

$h=v_{o}t+\frac{1}{2} gt^2$

where $h$ is the height, in this case 100m

$v_{o}$ the inicitial velocity wich is 0 since it came from rest

g is gravity and t is time

So we have:

$100=\frac{1}{2}(9.8m/s^2)t^2$

$t= \sqrt{\frac{200m}{9.8m/s^2} } =4.52s$

For the fist rock we need to find the time it takes to go up and go back down to the height it was launched:

that time is

$t_{1}=2v_{o}/g =2(15m/s)/9.8m/s^2=3.06s$

and the time the fist rock is going down from that point, we can find in a similar way we did for the fist rock, $t_{2}$ is:

$h=v_{o}t+\frac{1}{2} gt^2$

$100=(15m/s)t_{2}+\frac{1}{2}(9.8m/s^2)t_{2}^2\\0=-100 + (15m/s)t_{2}+\frac{1}{2}(9.8m/s^2)t_{2}^2$

$0=-100 + (15m/s)t_{2}+(4.9m/s^2)t_{2}^2$

solving as a quadratic equation for time we get:

$t_{2}=3.24s$

So, the total time for the first rock is:

$t_{1}+t_{2}= 3.06s + 3.24s =6.3s$

<u>This means that the second rock must be dropped 6.3s - 4.52 s = 1.78 seconds later, wich is the difference in the times that it takes for each rock to get to the bottom if the cliff.</u>

6 0

3 years ago