Answer
given,
time = 10 s
ship's speed = 5 Km/h
F = m a
a is the acceleration and m is mass.
In the first case
F₁=m x a₁
where a₁ = difference in velocity / time
F₁ is constant acceleration is also a constant.
Δv₁ = 5 x 0.278
Δv₁ = 1.39 m/s

a₁ = 0.139 m/s²
F₂ =m x a₂
F₃ = F₂ + F₁
Δv₃ = 19 x 0.278
Δv₃ = 5.282 m/s
a₃=Δv₂ / t

a₃ = 0.5282 m²/s
m a₃=m a₁ + m a₂
a₃ = a₂ + a₁
0.5282 = a₂ + 0.139
a₂=0.3892 m²/s
F₂ = m x 0.3892...........(1)
F₁ = m x 0.139...............(2)
F₂/F₁
ratio = 
ratio = 2.8
Answer:
frequency = 0.5 Hz and speed = 2 m/s
Explanation:
Given that,
The period of a wave, T = 2 s
Wavelength, 
If f be the frequency. So,
f = 1/T

Speed of a wave is given by :

So, the frequency of the wave is 0.5 Hz and speed is 2 m/s.
A sphere is charged with electrons to −9 × 10−6 C. The value given is the total charge of all the electrons present in the sphere. To calculate the number of electrons in the sphere, we divide the the total charge with the charge of one electron.
N = 9 × 10−6 C / 1.6 × 10−19 C
N = 5.6 x 10^13
Answer:
3.26mph
Explanation:
To calculate speed, use the formula distance/time. In this case, just divide 14.7 by 4.5.
Answer:
Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.
Explanation:
Since horse is working steadily, the power experimented by the horse (
), measured in watts, is at constant rate. Then, the work needed by the horse (
), measured in joules, is equal to that power multiplied by time (
), measured in seconds. That is:
(1)
If we know that
and
, then the work needed for the horse is:



Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.