How many sig figs are in 3252.6

A cake is removed from a 350◦F oven and placed on a cooling rack in a 70◦F room. After 30 minutes the cake is 200◦F. When will i

galben [10]

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

$\frac{dT}{dt}$ = -k(T-Ta)

$\frac{dy}{dt}$ = $\frac{d}{dt}$ (T(t) -Ta)

= $\frac{dT}{dt} -\frac{dTa}{dt} =\frac{dT}{dt}$ = -k(T-Ta)

-ky $\frac{dy}{dt}$ = -ky

T(t) -Ta = (To -Ta) $e^{-kt}$ T(t) = Ta+ (To -Ta) $e^{-kt}$

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 ) $e^{-k30}$

k = 0.025575

so here for T(t) = 100F

100 = 70 + ( 350 - 70 ) $e^{-0.025575*t}$

time = 87.33 min

so here 350 F to 100 F it take approx 87.33 min

5 0

3 years ago

A frog jumps for 4.0 seconds at a maximum horizontal distance of 0.8m. what is its velocity along the road?

Lerok [7]

Answer:

The frog's horizontal velocity is 0.2 m/s.

Explanation:

To solve this problem, we must first remember what velocity is and how we solve for it. Velocity can be solved for using the formula x/t, where x represents horizontal distance and t represents time (in seconds), that it takes to travel this distance. If we plug in the given numbers for these variables and solve, we get the following:

v = x/t

v = 0.8m/4s

v = 0.2 m/s

Therefore, the correct answer is 0.2 m/s. We can verify that these units are correct because the formula calls for distance divided by time, so meters per second is a sensible answer.

Hope this helps!

3 0

3 years ago

Sammy squirrel is steering his boat at a heading of 327 degree at 18mph. The current is flowing at 4mph at a heading of 60 degre

Tanya [424]

Answer:

59.97 º at 18.23 mph

Explanation:

To find Sammy's course you have to add the two velocities (vectors), 18 mph 327º and 4 mph 60º.

To add the two vectors analytically you decompose each vector into their vertical and horizontal components.

1. 18 mph 327º

Horizontal component: 18 mph × cos (327º) = 15.10 mph

Vertical component: 18 mph × sin (327º) = - 9.80 mph

Vector notation:

$15.10\hat i-9.80\hat j$

2. 4 mph 60º

Horizontal component: 4 mph × cos (60º) = 2.00 mph

Vertical component: 4 mph × sin (60º) = 3.46 mph

Vector notation:

$2.00\hat i+3.46\hat j$

3. Addition:

You add the corresponding components:

$15.10\hat i-9.80\hat j+2.00\hat i+3.46\hat j\\ \\ 17.10\hat i-6.34\hat j$

To find the magnitude use Pythagorean theorem:

$\sqrt{17.1^2+6.34^2}= 18.23$

4. Direction:

Use the tangent ratio:

$tan(\alpha )=opposite/adjacent=3.46/2.00=1.73$

Find the inverse:

arctan (1.73) ≈ 59.97º

5 0

3 years ago

The shortstop plays between first and second base. true or false

adell [148]

SINGLE TO RIGHT OR CENTER FIELD-On a single to center or right field the first baseman will be the cutoff to home. The shortstop will cover second base.

4 0

3 years ago

Which of the following is a vector quantity?

gizmo_the_mogwai [7]

Answer:

B. 30 m down

Explanation:

In physics we have two types of quantities:

- Scalar quantity: it is a quantity which only has a magnitude (e.g: mass and time are scalar quantities, since they only have a magnitude)

- Vector quantity: it is a quantity which has both a magnitude and a direction (e.g: velocity is a vector quantity, since it has a magnitude (the speed) and a direction)

In this problem, we have:

A. 100 ounces of water --> scalar (this is a volume, which has only a magnitude)

B. 30 m down --> vector (this is a displacement, which has both a magnitude (30 m) and a direction (down)

C. 88 mi/s --> scalar (this is a speed, which has only a magnitude)

D. 45 gallons in a bucket --> scalar (this is a volume, which has only a magnitude)

So, the correct option is B.

4 0

3 years ago