Answer:
A
Explanation:
A virtual image is on the same side as the object, which by convention is drawn on the left side. So -di would represent a virtual image.
Answer:
40 kg•m/s
Explanation:
momentum (p) = mass (kg) × velocity (m/s)
Answer: A. 200J
Therefore, the workdone by the heat engine is 200J
Explanation:
Given ;
The efficiency of the heat engine is E = 20% = 0.2
Heat loss L= 800J
For an heat engine the efficiency is measured by the amount of workdone by the heat engine when compared to the heat generated.
Efficiency E = workdone/heat generated × 100%
Heat generated G= workdone W + heat loss L
G = W + L
According to the question.
W = 20% of G
W = 0.2G ......1
L = 80% of G
L = 0.8G
G = L/0.8 ......2
Substituting equation 2 to 1
W = 0.2(L/0.8)
And L = 800J
W = 0.2(800/0.8)
W = 200J
Therefore, the workdone by the heat engine is 200J
Answer:
A. Fluorine
Explanation:
This is because it has the smallest atomic radius.

Answer:
2.22m/s
Explanation:
Given parameters:
M1 = 60kg
M2 = 75kg
V1 = 0m/s
V2 = 4m/s
Unknown;
Velocity after collision = ?
Solution:
To solve this problem, we must understand that the momentum before and after collision of the bodies must be the same;
M1 V1 + M2 V2 = v(M1 + M2)
So;
60 x 0 + 75 x 4 = v (60 +75)
300 = 135v
v = 2.22m/s