Answer:
The time for the cake to cool off to room temperature is
approximately 30 minutes.
Let = F be the temperature and T that of the body
Explanation:
Our Tm = 70, the initial-value problem is
= <em>k</em>(T − 70), T(0) = 300
Solving the equation, we get
= <em>kdt</em>
In [T-70]= <em>kt </em>+
T = 70 +
Finding he value for using the initial value of T (0)= 300, therefore we get:
300=70+
= 230 therefore
T= 70+ 230
Finding the value for <em>k </em>using T (3) = 200, therefore we get
T (3) = 200
=
<em>K </em>= in
= -0.19018
Therefore
T(t) = 70+230
<span>So we want to know which statement is true for the body of mass m=2000kg that is lifted to a height of h=15m in t=15 s. Lets calculate each of the following: Gravity force on the body is F=m*g=2000*9.81=19620 N so a is FALSE. Potential energy of the body when it is lifted to the height of 15 m is Ep=m*g*h=2000*9.81*15=294300 J so b is FALSE. Work to lift the body is: W=Fg*h=2000*9.81*15= Ep=294300 J so c is FALSE. Power P=W/t=294300/15=19620 W So d is TRUE. </span>
A mixture is 2 or more different elements not bonded together
Example : N2 or O2
Answer:
In physics, a charged particle is a particle with an electric charge. ... It can also be an electron or a proton, or another elementary particle, which are all believed to have the same charge (except antimatter). Another charged particle may be an atomic nucleus devoid of electrons, such as an alpha particle. Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge and a rest mass equal to 1.67493 × 10−27 kg—marginally greater than that of the proton but nearly 1,839 times greater than that of the electron.
Explanation:
Answer:
During stage 3 - late expanding (of demogrpahic transition model)
Explanation:
During stage 3, birth rate begins to decline as infant mortality is lower and women have more access to education, family planning, and contraceptives. Children are not needed as "free labor" as they might have been in earlier stages.