A person standing on the moon watching the earth rotate
Answer:
Scenario A, B and E is True.
Explanation:
Scenario A) True. Removing carbon dioxide from atmosphere decreases greenhouse effect of atmosphere. Thus, temperature rise decreases.
Scenario B) True. The more evaporation creates the more greenhouse effect. Therefore, temperature rise increases.
Scenario C) False. Removing carbon dioxide from atmosphere decreases greenhouse effect of atmosphere. Thus, temperature rise decreases.
Scenario D) False. The more evaporation creates the more greenhouse effect. Therefore, temperature rise increases.
Scenario E) True. If reflected radiation increases from Earth, temperature rise of the Earth will decrease. Ice cover increases reflectivity which leads temperature level decrease.
Scenario F) False. If reflected radiation increases from Earth, temperature rise of the Earth will decrease. Ice cover increases reflectivity which leads temperature level decrease.
Answer:
The false statement is in option 'd': The center of mass of an object must lie within the object.
Explanation:
Center of mass is a theoretical point in a system of particles where the whole mass of the system is assumed to be concentrated.
Mathematically the position vector of center of mass is defined as
where,
is the position vector of the mass dm.
As we can see for homogenous symmetrical objects such as a sphere,cube,disc the center of mass is located at the centroid of the shapes itself but in many shapes it is located outside the body also.
Examples of shapes in which center of mass is located outside the body:
1) Horseshoe shaped body.
2) A thin ring.
In many cases we can make shapes of bodies whose center of mass lies outside the body.
Answer:
480J
Explanation:
Using the formula:
Delta U = Q - W
Q:Heat (J)
Delta U: Changes in internal Energy (J)
W:Work (J)
We can plug in the give numbers, Q and W.
Delta U = 658J - 178J = 480J
A) Work energy relation;
Work =ΔKE ; work done = Force × distance, while, Kinetic energy = 1/2 MV²
F.s = 1/2mv²
F× 4×10^-2 = 1/2 × 5 ×10^-3 × (600)²
F = 900/0.04
= 22500 N
Therefore, force is 22500 N
b) From newton's second law of motion;
F = Ma
Thus; a = F/m
= 22500/(5×10^-3)
= 4,500,000 m/s²
But v = u-at
0 = 600- 4500,000 t
t = 1.33 × 10^-4 seconds
