Answer:
The value is
Explanation:
From the question we are told that
The height is 
The height of the burning roof is 
The horizontal distance is 
The height of the truck is 
Generally the time for the water to hit the roof from the hose is mathematically represented as

=> 
=> 
Generally the velocity of the water is mathematically evaluated as
Generally from Bernoulli's Equation we have that

Here
Answer:
displacement= 30 m towards south, distance= 210m
Explanation:
Distance (scalar quantity) how much ground an object has covered.
Displacement (vector quantity) refers to how far out of place an object is it is the object's overall change in position.
Basically meaning for displacement the directions will be very key
D for Displacement
D= D1+D2
D= 120 (S) + 90 m (N)
Must be in same direction
D= 120 (S) + (-90 m) (S)
D= 30 m (S)
and for distance you are simply just adding how much distance they have covered
so d= d1+d2
d= 90m + 120m
d= 210m
The density of the material would be 4.1 g/cm³.
Density is calculated by dividing the mass by the volume.
D=m÷v
D=45 g÷11 cm³
D=4.1 g/cm³
Answer:
M[min] = M[basket+people+ balloon, not gas] * ΔR/R[b]
ΔR is the difference in density between the gas inside and surrounding the balloon.
R[b] is the density of gas inside the baloon.
====================================
Let V be the volume of helium required.
Upthrust on helium = Weight of the volume of air displaced = Density of air * g * Volume of helium = 1.225 * g * V
U = 1.225gV newtons
----
Weight of Helium = Volume of Helium * Density of Helium * g
W[h] = 0.18gV N
Net Upward force produced by helium, F = Upthrust - Weight = (1.225-0.18) gV = 1.045gV N -----
Weight of 260kg = 2549.7 N
Then to lift the whole thing, F > 2549.7
So minimal F would be 2549.7
----
1.045gV = 2549.7
V = 248.8 m^3
Mass of helium required = V * Density of Helium = 248.8 * 0.18 = 44.8kg (3sf)
=====
Let the density of the surroundings be R
Then U-W = (1-0.9)RgV = 0.1RgV
So 0.1RgV = 2549.7 N
V = 2549.7 / 0.1Rg
Assuming that R is again 1.255, V = 2071.7 m^3
Then mass of hot air required = 230.2 * 0.9R = 2340 kg
Notice from this that M = 2549.7/0.9Rg * 0.1R so
M[min] = Weight of basket * (difference in density between balloon's gas and surroundings / density of gas in balloon)
M[min] = M[basket] * ΔR/R[b]
<h2>The different forces acting on the ball while its in air</h2>
Amy throws a softball through the air. Applied, drag and gravitational forces are acting on the ball while it’s in the air. The softball experiences force as a result of Amy’s throw. As the ball moves, it experiences from the air it passes through.
It also experiences a downward pull because earth has the property to attract everything which is on the earth towards it. The ball is moving in the air but earth applies force on the ball to get back on the ground. Hence, in this way, gravitational force applies.
There is also a drag force which results due to friction that is present in the air. It resist to move ball in the air and there will also be applied force which is given by a person who throws by applying force.