Answer??????????????

A 10-kg rock falls from a height of 8-m above the ground. What is the kinetic energy of the rock just before it hits the ground?

pishuonlain [190]

Answer: 800

Explanation:

1/2 x m x v^2 = m x g x h

KE = 10 x 10 x 8

KE= 800

3 0

2 years ago

Ccording to coulomb's law, which pair of charged particles has the lowest potential energy? according to coulomb's law, which pa

Sladkaya [172]

Coulombs law says that the force between any two charges depends on the amount of charges and distance between them. This force is directly proportional to the magnitude of the two charges and inversely proportional to the distance between them.

$F=k\frac{|q_1| |q_2|}{r^2}$

where $q_1\hspace{1mm}and\hspace{1mm}q_2$ are charges, $r$ is the distance between them and k is the coulomb constant.

case 1:

$q_1=-e\\ q_2=+3e\\ r=100pm\\ \Rightarrow F=k\frac{|-e||3e|}{(100pm)^2}=3ke^2\times10^8$

case 2

$q_1=-e\\ q_2=+2e\\ r=100pm\\ \Rightarrow F=k\frac{|-e||2e|}{(100pm)^2}=2ke^2\times10^8$

case 3:

$q_1=-e\\ q_2=+e\\ r=100pm\\ \Rightarrow F=k\frac{|-e||e|}{(200pm)^2}=0.25ke^2\times10^8$

Comparing the 3 cases:

The maximum potential force according to coulombs law is between -1 charge and +3 charge separated by a distance of 100 pm.

3 0

2 years ago

Read 2 more answers

A 6 kg box with initial speed 5 m/s slides across the floor and comes to a stop after 1.9 s. What is the coefficient of kinetic

Ilia_Sergeevich [38]

Answer:

$\mu_k=0.27$

Explanation:

According to the free body diagram, in this case, we have:

$\sum F_x:-F_k=ma\\\sum F_y:N=mg$

Recall that the force of friction is given by:

$F_k=\mu_k N$

Replacing and solving for the coefficient of kinetic friction:

$-\mu_kN=ma\\-\mu_k(mg)=ma\\\mu_k=-\frac{a}{g}$

We have an uniformly accelerated motion. Thus, the acceleration is defined as:

$a=\frac{v_f-v_0}{t}\\a=\frac{0-5\frac{m}{s}}{1.9s}\\a=-2.63\frac{m}{s^2}$

Finally, we calculate $\mu_k$ :

$\mu_k=-\frac{-2.63\frac{m}{s^2}}{9.8\frac{m}{s^2}}\\\mu_k=0.27$

4 0

3 years ago

Elements that give up electrons easily are called ________

valina [46]

Elements that give up electrons easily are called <u>metals.</u>

hope this helps!

5 0

2 years ago

In what direction must the current I2 flow in the straight wire in order to create a field at the center of the loop in the dire

guajiro [1.7K]

Answer:

Right to left

Explanation:

From right hand thumb rule, the magnetic field at the centre of loop points out of the plane of paper. Thus the straight wire current should create magnetic field into the plane of paper at the centre. Hence the direction of current in long wire should be from right to left

6 0

3 years ago