Answer:

Explanation:
Given:
- mass of John,

- mass of William,

- length of slide,

(A)
height between John and William, 
<u>Using the equation of motion:</u>

where:
v_J = final velocity of John at the end of the slide
u_J = initial velocity of John at the top of the slide = 0
Now putting respective :


<u>Now using the law of conservation of momentum at the bottom of the slide:</u>
<em>Sum of initial momentum of kids before & after collision must be equal.</em>

where: v = velocity with which they move together after collision

is the velocity with which they leave the slide.
(B)
- frictional force due to mud,

<u>Now we find the force along the slide due to the body weight:</u>



<em><u>Hence the net force along the slide:</u></em>

<em>Now the acceleration of John:</em>



<u>Now the new velocity:</u>



Hence the new velocity is slower by

Pressure and heat. I hope this helps
Answer:
The value is 
Explanation:
From the question we are told that
The power rating of the stove is 
The duration of its use everyday is
The rating of the light bulbs is 
The number is 
The power rating of the total bulb is 
The duration of its use everyday is 
The power rating of miscellaneous appliance 
The duration of its use everyday is 
The power rating of hot water 
The duration of its use everyday is 
Generally the total electrical energy used in 1 month is mathematically represented as

=> 
=> 
=> 
Generally the monthly electricity bill is mathematically represented as

=> 
Answer: V = 15 m/s
Explanation:
As stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. The observed frequency the car will be experiencing will be addition of the two frequency. That is,
F = 2.1 × 10^10 + 1030 = 2.100000103×10^10Hz
Using doppler effect formula
F = C/ ( C - V) × f
Where
F = observed frequency
f = source frequency
C = speed of light = 3×10^8
V = speed of the car
Substitute all the parameters into the formula
2.100000103×10^10 = 3×10^8/(3×10^8 -V) × 2.1×10^10
2.100000103×10^10/2.1×10^10 = 3×108/(3×10^8 - V)
1.000000049 = 3×10^8/(3×10^8 - V)
Cross multiply
300000014.7 - 1.000000049V = 3×10^8
Collect the like terms
1.000000049V = 14.71429
Make V the subject of formula
V = 14.71429/1.000000049
V = 14.7 m/s
The speed of the car is 15 m/s approximately
The cube has 6 equal, square, foil faces. The mass of foil for each face is (380/6) milligrams.
The surface area of each piece is (380)/(6•11) cm^2.
The length of each side of the piece is √(380/6•11) cm
That's about 2.4 cm .
It's a cute little foil cube, just under 1-inch each way.