Drake lifted a couch a height of 0.2 meters in 1.3 seconds. He did 300 j of work. how much power did drake use?

A boat is able to move through still water at 20 m/s. It makes a round trip to a town 3.0 km upstream. If the river flows at 5m/

Salsk061 [2.6K]

Answer:

Option e) 320 s

Explanation:

Here, distance = 3.0 km = 3000 m

The velocity of boat when it is going upstream;

Upstream velocity = velocity of boat in still water - velocity of river flow

So, Upstream velocity $=20m/s-5m/s=15m/s$

So,Time to go upstream

$(t_{1}) =\frac{Distance}{Velocity}=\frac{3000m}{15m/s} =200 s$

The velocity of boat when it is going downstream;

Downstream velocity = velocity of boat in still water + velocity of river flow

So, Downstream velocity $=20m/s+5m/s=25m/s$

So,Time to go downstream

$(t_{2}) =\frac{Distance}{Velocity}=\frac{3000m}{25m/s} =120 s$

So, total time (t) = $t_{1}+t_{2}=200s+120 s=320s$

Option E is the correct answer.

3 0

3 years ago

Read 2 more answers

What is the maximum value the string tension can have before the can slips? The coefficient of static friction between the can a

Naya [18.7K]

Answer:

T= 38.38 N

Explanation:

Here

mass of can = m = 3 kg

g= 9.8 m/sec2

angle θ = 40°

From figure we see the vertical and horizontal component of tension force T

If the can is to slip - then horizontal component of tension force should become equal to force of friction.

First we find force of friction

Fs= μ R

where

μ = 0.76

R = weight of can = mg = 3 × 9.8 = 29.4 N

Now horizontal component of tension

Tx= T cos 40 = T× 0.7660 N

==>T× 0.7660 = 29.4

==> T= 38.38 N

8 0

3 years ago

Which of the following is the best thermal insulator?

Vera_Pavlovna [14]

B. Aluminum is possibly correct

4 0

3 years ago

Estimate the volume of a typical house (2050 feet squared in size and 10 feet tall) answer in units of meters squared

Aloiza [94]

Answer:

$Volume = 6248.48 m^{3}$

Explanation:

Given:

The area of the house $A = 2050\ ft^{2}$

The height of the house $h=10\ ft$

We need to find the volume of a typical house.

Solution:

We find the volume of the house by multiplying the area of the house and height of the house.

$Volume = Area\times height$

$Volume = A\times h$

Area and height of the house are known, so we substitute these value in above equation.

$Volume = 2050\times 10$

$Volume = 20500\ ft^{3}$

Now we convert the unit from feet to meter.

Divide the volume by 3.2808 for $m^{3}$

$Volume = \frac{20500}{3.2808}$

$Volume = 6248.48\ m^{3}$

Therefore, the volume of the house is $6248.48 m^{3}$

8 0

3 years ago

I NEED HELP WITH THE LAST QUESTION PLS HELP!! (The one below 8)

maksim [4K]

Answer:

I. 6 cells .

II. Series connection.

Explanation:

I. Determination of the number of cells needed.

From the question given above,

Total voltage (V) = 9 V

1.5 V = 1 cell

Number of cells needed =?

The number of cells needed to make the 9V battery can be obtained as follow:

1.5 V = 1 cell

Therefore,

9 V = 9 V × 1 cell / 1.5 V

9 V = 6 cells

Thus, 6 cells of 1.5 V each is needed

II. Determination of the connection line

Total voltage (Vₜ) = 9 V

Cell 1 (V₁) = 1.5 V

Cell 2 (V₂) = 1.5 V

Cell 3 (V₃) = 1.5 V

Cell 4 (V₄) = 1.5 V

Cell 5 (V₅) = 1.5 V

Cell 6(V₆ ) = 1.5 V

For parrall connection:

Vₜ = V₁ = V₂ = V₃ = V₄ = V₅ = V₆

9 V = 1.5 V =... = 1.5 V

For series connection:

Vₜ = V₁ + V₂ + V₃ + V₄ + V₅ + V₆

9 = 1.5 + 1.5 + 1.5 + 1.5 + 1.5 + 1.5

9 V = 9 V

From the illustration above, we can see that series connection of each cells will give a total volt of 9 V unlike the parallel connection which resulted to 1.5 V.

Therfore, the cells should be arranged in series connection

8 0

3 years ago