Answer:
Given that,
- Power = 2000 W
- time = 60 seconds
- distance= 10m
Power = work done ÷ time
Here, since the movement is vertical, w = mgh
So,
Power = mgh÷t
2000 = (m × 9.8 ×10) ÷ 60
m = (2000 ×60) ÷98
m = 1224.5kg
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]
Answer: 0.6m
Explanation:
Given that:
force = 4.5 N
Work done = 2.7J
Distance moved by the book = ?
Since work is done when force is applied on an object over a distance, apply the formula:
work = force x distance
2.7J = 4.5N x distance
Distance = (2.7J / 4.5N)
Distance = 0.6 m
Thus, the book was moved 0.6 metres far
Answer:
95 J
Explanation:
You can calculate efficiency by dividing useful output by total input, then multiplying it to 100.
So the foumula goes like:
Efficiency= (Useful output/Total input)x100
In this question,
Efficiency= 95%
Useful output= x
Total input= 200
Therefore;
95=(x/200)x100
0.95=x/100
x=0.95x100
x=95 Joules
Answer:
Groceries stay in the bag.
Explanation:
Given:
Maximum force = 250 N
Bag filled with = 20 kg
Lifted acceleration = 
Solution:
We need to calculate the exerted force on the grocery bag by using Newton's second law.
Where:
F = Exerted force on the object.
m = Mass of the object in kg
a = Acceleration of the object in 
Now, we substitute m = 20 kg and a = in Newton's second law,
Since, the exerted force on the bag is less than 250 N, the groceries will stay in the bag.
