Answer:
D lower energy waves is most likely the safest if one is exposed to.
You've got a 69.0-kg wooden crate on a wooden floor. The box can withstand a force of up to 338N in a horizontal direction without being moved. Following this, the wooden creates moving stats.
In order to calculate the friction coefficient, divide the force pushing two objects together by the force acting between them. friction coefficient might be 0 or one. They can be split into two categories: friction coefficient that is static. Kinetic friction coefficient (also known as sliding coefficient of friction).
the acceleration brought on by the gravitational pull of large masses generally, gravitational , often known as the acceleration brought on by the Earth's gravitational pull and centrifugal force,
F= friction coefficient *M*g
F= 0.5*69*9.8
F=338N
Learn more about gravitational here
brainly.com/question/3009841
#SPJ4
Answer:
96 s.
Explanation:
(a)
From the question,
Q = cm(t₂-t₁)................... Equation 1
Where Q = heat required to boil the water, c = specific heat capacity of the water, m = mass of the water, t₂ = final temperature of water, t₁ = initial temperature of water
Note: The boiling point of water = 100 °C
Given: c = 4200 J/kg.°C, t₂ = 100 °C, t₁ = 20 °C
mass of water = density×volume
m = D×v, Where D = 1000 kg/m³, v = 1.00 L = 0.001 m³
Hence, m = 1000×0.001 = 1 kg.
Substitute into equation 1
Q = 4200×1(100-20)
Q = 4200×8
Q = 33600 J.
But,
P = Q/t................... Equation 2
make t the subject of the equation
t = Q/P................. Equation 3
Where P = power, t = time
From the question,
70 % of the available energy is absorbed by water.
P = 0.7×500 = 350 W.
Substitute into equation 2
t = 33600/350
t = 96 s.
The true statements about magnetic fields and forces will be A,D and E.
<h3>What is a magnet?</h3>
An iron piece,alloy, or other substance with its constituent atoms arranged in such a way that it shows magnetism qualities,
The function of the magnet is attracting other iron-containing objects or aligning itself in a magnetic field.
There are two poles of the magnet;
1. North Pole.
2. South Pole.
The same poles repel each other, while the opposite poles attract each other. In a sense, south-south and north-north repel. While the north-south and the south-north attract each other.
The correct statements are;
(A). The north pole attracts the south pole of a magnet.
(D)Forces caused by magnetic fields are weaker farther from the magnet.
(E)Magnetic forces can act on an object even if the object isn't touching the magnet.
Hence, the true statements about magnetic fields and forces will be A,D and E.
To learn more about the magnet, refer to the link;
brainly.com/question/13026686
#SPJ1
