That two ways are known as:
1) Series connection
2) Parallel connection
Answer:
a) 4.9W b) 3.82W
Explanation:
Stefan-Boltzmann law of radiation formulae:
Q/t (W) = sigma* e*A*T^4
Sigma = 5.67*10^-8 j/sm^2K^4 (Stefano Boltzmann constant)
e = emissivity
T = absolute temperature in kelvin and A = area in m^2
a) Q/t = 140/10000(m^2) * 0.87* 5.67* 10^-8* (290^4) = 4.9W
b) without hair the
Q/t = 140/ 10000(m^2) *0.68* 5.67* 10^-8* (290^4)
= 3.82W
First we need to turn Aouita's time for the race into seconds. There are
60 seconds in a minute, so 7 minutes and 29.45 seconds is (7 x 60) +
29.45 = 449.45. He ran 3000 meters in that time, so his average speed
was 3000 meters divided by 449.45 seconds. 3000 / 449.45 = 6.67 m/s. So,
on average, he covered 6.67 meters (more than 21 feet!) during each
second of the race.
Gravitational force = Gxm1xm2 /r^2
This equation depends only upon object's masses and distance between them. So option b is correct
Answer:
A) 10 m/s
Explanation:
We know that according to conservation of momentum,
m1v1 + m2v2 = m1u1 + m2u2 ..............(equation 1)
where m1 and m2 are masses of two bodies, v1 and v2 are initial velocity before collision and u1 and u2 are final velocities after collision respectively.
From the given data
If truck and car are two bodies
truck : m1 = 2000 Kg v1 = 5 m/s u1 = 0
car : m2 = 1000 kg v2 = 0 u2 = ?
final velocity of truck and initial velocity of car are static because the objects were at rest in the respective time.
substituting the values in equation 1, we get
(2000 x 5) + 0 = 0 + (1000 x u2)
u2 = 
x 5
= 10 m/s
Hence after collision, car moves at a velocity of 10 m/s
