Answer:5m
Explanation:a=-10m/s (since it moved upwards against gravity)
V=0
U=10m/s
v2=u2+2as
0= 100-20s
20s=100
s=5m
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
0.078 times the orbital radius r of the earth around our sun is the exoplanet's orbital radius around its sun.
Answer: Option B
<u>Explanation:</u>
Given that planet is revolving around the earth so from the statement of centrifugal force, we know that any

The orbit’s period is given by,

Where,
= Earth’s period
= planet’s period
= sun’s mass
= earth’s radius
Now,

As, planet mass is equal to 0.7 times the sun mass, so

Taking the ratios of both equation, we get,





Given
and 


Gravity. Hope this helps!
<span>When temperature increases, particles in an object speed up, which means an increase in thermal energy. Since the particles are moving more now, the potential energy decreases, therefore kinetic energy increases.
Overall, when temp goes up, thermal energy goes up, which leads to an increase in kinetic energy.</span>