Answer:
Power = 130 watt
Explanation:
Power is described as the ability to do work, it is also defined as the amount of work in Joules done in a given time in seconds. Mathematically, it is represented as:

In this example, power is calculated as follows:
Work = 39000 J
Time = 5 minutes
converting the time from minutes to seconds:
1 minute = 60 seconds
∴ 5 minutes = 60 × 5 = 300 seconds

N:B the unit for power can also be represented as Joules/seconds or J/s or JS⁻¹
ananı var ya ananı
kodumun abd lisi aptal cajhil özürlü
Answer:
D. 550 Hz
Explanation:
Frequency for string is given by

where v is the speed of the wave, L = m is the length
Frequency is inversely proportional to the Length of the string

from above relation we can write

The newly shortened string has 4/5 the length of the full string .i,e

Hence option D is correct
The total momentum of the system is preserved through the collision.
Note that momentum is
P = m*v
where m = mass
v = velocity.
Initial momentum:
P1 = (30000 kg)*(2 m/s) = 60000 (kg-m)/s for the moving car
P2 = 0 for the starionary car.
Final momentum:
P3 = (30000 + 30000)*v = 60000v (kg-m)/s
Because momentum is preserved,
P3 = P1 + P2
60000v = 60000
v = 1 m/s
The final velocity is 1 m/s.
Answer: 1.0 m/s
Answer:
Betelgeuse is 640 light years away from earth.
Explanation:
A light-year is an astronomical unit to measure the distance the light travels in a calendar year.
If the light from a star takes 640 years to reach us, then that star its 640ly away from us.
Betelgeuse has been labeled as a Variant Star, which means that its brightness can fluctuate over the course of years, this has made difficult for astronomers to measure the exact distance of the star. Right now the star is estimated to be around 613 and 881ly away from earth, although, for the sake of your second question, we will take 640 years as our estimated value.
In 1380 (640 years ago) the Battle of Kulikovo took place. A battle of remarkable importance to Russian history, in which the Russian army, led by Prince Dmitry of Moscow, defeated the Mongol army, defining a turning point in the Mongol dominance, and setting the bases for what Russia is today.