Answer:
The point straight overhead on the celestial sphere for any observer is called the zenith and is always 90 degrees from the horizon. The arc that goes through the north point on the horizon, zenith, and south point on the horizon is called the meridian.
From any location on Earth you see only half of the celestial sphere, the half above the horizon.
If you stood at the North Pole of Earth, for example, you would see the north celestial pole overhead, at your zenith. The celestial equator, 90° from the celestial poles, would lie along your horizon.
Answer:
The value of new value of angular speed of merry go round.
= 0.96 
Explanation:
Given data
r = 1.4 m
Moment of inertia
= 265 kg - 
11 RPM


= 1.15 
From conservation of momentum principal
------- (1)



Put all the values in equation (1)
265 × 1.15 = 317.92 × 
= 0.96 
This is the value of new value of angular speed of merry go round.
Answer: machine's efficiency = 82.2%
Explanation:
Efficiency of a machine is the capability of a machine to convert input to output without waste.
It can be expressed as
Efficiency = output/ input × 100%
Output = 7,023N
Imput = 8,542N
Efficiency = 7,023N/8,542N × 100%
Efficiency = 82.2%
Answer:

Explanation:
Given:
- temperature of skin,

- initial temperature of steam vapour,

- latent heat of steam,

- mass of steam,

- specific heat of water,

- final temperature,

<em>Assuming that no heat is lost in the surrounding.</em>
<u>We know:</u>

<u>Now the total heat given by the steam to form water at the given conditions:</u>
..............................(1)
where:
latent heat given out by vapour to form water of 100°C
heat given by water of 100°C to come at 34°C.
putting respective values in eq. (1)



is the heat transferred to the skin.
Answer:A 2.2kg block of ice slides across a rough floor. Its initial velocity is 2.5m/s and its final velocity is 0.50m/s. How much of the ice block melted as a result of the work done by friction? (Latent Heat of water is 3.3*10^5J/kg)
Explanation: