Answer: a. 126.21secs
b. 12.621 meters.
Explanation:
Given data:
Speed of tortoise = 0.1m/s.
Speed of hare = 2m/s.
Solution:
a. Distance traveled = Speed* Time
Speed of tortoise = 0.1 m/s
Speed of hare = 20*0.1 m/s = 2 m/s
2 minutes = 2* 60 s = 120 s
Let the time taken for the race be t seconds.
• Distance moved by tortoise
= (0.1 /s)* (t s)
= 0.1*t meter
•Hare has run for a time of (t - 120)s.
distance moved by hare
= Speed * Time
= (2 m/s)*(t- 120)s
= (2t - 240) meter.
Since hare is 20 cm (0.2 m) behind the tortoise, therefore
(0.1*t - 0.2) meter
= (2t - 240) meter
0.1*t - 0.2 = 2t - 240
Collect like terms
239.8 = 1.9t
Divide both sides by 1.9
t = 126.21secs
The race lasted for 126.21secs
b. Length of race
= Distance moved by tortoise
= 0.1*126.21 meter
= 12.621 meter
The length of the race is 12.621 meters.
Answer:
F' = 800 N
Explanation:
The electrical force between charges is 400 N.
The electrical force between two charges is given by :
If q₁' = 2q₁, new force becomes,
So, the new force becomes 800 N.
Answer:
20.58 kJ
Explanation:
mass, m = 75 kg
height, h = 28 m
Work = m x g x h
W = 75 x 9.8 x 28
W = 20580 J
W = 20.58 kJ
Thus, the work done is 20.58 kJ.
Potential Energy = mgh ,
mass = 1.4 kg, g ≈ 10 m/s², h = 0.8m
Potential Energy = mgh = 1.4 * 10 * 0.8 = 11.2 N
Potential Energy added = 11.2 N
Answer:
Jupiter has an internal heat source.
Explanation:
It is believed that most of this heat is the residual (left over) heat from the time when formation of early Solar nebula took place. Jupiter absorbs energy from the Sun in the form of light and the coverts it into heat and later releases this heat in the form of thermal radiation.
It is recorded that Jupiter emits almost twice amount of energy from the amount which it receives from the sun. It is this internal source of energy and sunlight which provide energy to Jupiter's atmosphere.
However, this phenomenon of internal heat source is also seen in other celestial bodies as well such as Saturn, Neptune, Stars, etc.