Answer:
350 F to 100 F it take approx 87.33 min
Explanation:
given data
oven = 350◦F
cooling rack = 70◦F
time = 30 min
cake = 200◦F
solution
we apply here Newtons law of cooling
= -k(T-Ta)
=
(T(t) -Ta)
=
= -k(T-Ta)
-ky
= -ky
T(t) -Ta = (To -Ta)
T(t) = Ta+ (To -Ta)
put her value for time 30 min and T(t) = 200◦F and To =350◦F and Ta = 70◦F
so here
200 = 70 + ( 350 - 70 ) 
k = 0.025575
so here for T(t) = 100F
100 = 70 + ( 350 - 70 ) 
time = 87.33 min
so here 350 F to 100 F it take approx 87.33 min
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the
tree and the bear is
Answer:
400 g
Explanation:
The computation of the number of grams in the original sample is shown below:
Given that
half-life = 5.26 years
total time of decay = 15.8 years
final amount = 50.0 g
Now based on the above information
number of half-lives past is
= 15.8 ÷ 5.26
= 3 half-lives
Now
3 half-lives = 1 ÷ 8 remains = 50.0 g
So, the number of grams would be
= 50.0 g × 8
= 400 g
Answer:
ΔK = 24 joules.
Explanation:
Δ
Work done on the object
Work is equal to the dot product of force supplied and the displacement of the object.
* Δ
Δ
can be found by subtracting the vectors (7.0, -8.0) and (11.0, -5.0), which is written as Δ
= (11.0 - 7.0, -5.0 - -8.0) which equals (4.0, 3.0).
This gives us
*
=
=
J
We know the formulas for momentum and energy. But they both involve the mass of
the object, and we don't know the mass of the baseball. What can we do ?
It's not a catastrophe. The question only asks which one is bigger. If we're clever,
we can answer that without ever knowing how much the momentum or the energy
actually is. We know that both baseballs have the same mass, so let's just call it
' M ' and not worry about what it really is.
<u>Momentum of anything = (mass) x (speed)</u>
Momentum of the first baseball = (M) x (4 m/s) = 4M
Momentum of the second one = (M) x (16 m/s) = 16M
The second baseball has 4 times as much momentum as the first one has.
<u>Kinetic energy of anything = 1/2 (mass) x (speed squared)</u>
KE of the first baseball = 1/2 (M) x (4 squared) = 8M
KE of the second one = 1/2 (M) x (16 squared) = 128M
The second baseball has 16 times as much kinetic energy as the first one has.