Answer:
Explanation:
Force F = 20 t² N so force is variable.
friction on the crate = mgμ , μ is coefficient of kinetic friction , m is mass
Net force
= F - mgμ
= 20 t² - mgμ = m dv / dt ( Newton's 2 nd law )
m dv = (20 t² - mgμ ) dt
Integrating on both sides,
m v = 20 (t³ / 3) - mgμ t
Putting the values ,
25 x v = 20 x 4³/3 - 25 x 9.8 x .25 x 4
25 v = 426.67 - 245
25 v = 181.67
v = 7.27
v = 7.27 m /s
Answer:
Explanation:
Given:
- Initial pressure of nitrogen,
- initial temperature,
- polytropic index,
- initial volume,
- work done in the process,
<u>For heat interaction during the polytropic process we have:</u>
<u>For ideal gas we have the Gas Law:</u>
<u>For work we have the relation:</u>
putting respective values
We know entropy change:
Reservoir i think. i’m not sure
Answer:
A galaxy with a disk and central bulge like a spiral galaxy, but with no spiral arms
Explanation:
A Lenticular galaxy is a kind of galaxy intermediate between elliptical galaxy and a spiral galaxy in the Morphological classification system of galaxies. They have a central bulge or disc just like a Spiral galaxy but lacks the arms of spiral galaxy. If looked edge on they appear to be spiral and if looked face on they appear to be elliptical.
The absence of spiral arms can be attributed to the absence of star formation. They mainly consists of ageing stars.
Answer:
d. 149 ⁰C.
Explanation:
Given;
mass of the block of ice, m = 2 kg
specific heat capacity of the ice, C = 2090 J/(kgK)
initial temperature of the ice, t₁ = -90 ⁰C
heat added to the ice, H = 1,000,000 J
let the final temperature of the ice = t₂
The final temperature of the ice after adding the heat is calculated as follows;
Therefore, the new temperature of the water is 149 ⁰C.