Answer:
The formula for speed is speed=<u>d</u><u>i</u><u>s</u><u>t</u><u>a</u><u>n</u><u>c</u><u>e</u>
time
Explanation:
to work out what the units are for speed,you need to know the units for distance and time.In this example,distance is in metres(m) and time is in seconds (s) , so the units for speed is metre per second (m/s).
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: you would use a thermometer
Explanation: why a thermometer? Because a thermometer is the only way a solution can be measured in the context of temperatures. By only way, I mean the hold of the device mentioned in the question
Given:
m₁ = 1540 g, mass of iron horseshoe
T₁ = 1445 °C, initial temperature of horseshoe
c₁ = 0.4494 J/(g-°C), specific heat
m₂ = 4280 g, mass of water
T₂ = 23.1 C, initial temperature of water
c₂ = 4.18 J/(g-°C), specific heat of water
L = 947,000 J heat absorbed by the water.
Let the final temperature be T °C.
For energy balance,
m₁c₁(T₁ - T) = m₂c₂(T - T₂) + L
(1540 g)*(0.4494 J/(g-C))*(1445-T C) = (4280 g)*(4.18 J/(g-C))*(T-23.1 C) + 947000 J
692.076(1445 - T) = 17890(T - 23.1) + 947000
10⁶ - 692.076T = 17890T - 413259 + 947000
466259 = 18582.076T
T = 25.09 °C
Answer: 25.1 °C
Answer:
The workdone by Jack is 
The workdone by Jill is 
The final velocity is 
Explanation:
From the question we are given that
The mass of the boat is 
The initial position of the boat is 
The Final position of the boat is 
The Force exerted by Jack 
The Force exerted by Jill 
Now to obtain the displacement made we are to subtract the final position from the initial position


Now that we have obtained the displacement we can obtain the Workdone
which is mathematically represented as
The amount of workdone by jack would be

![= [(-420\r i +0\r j +210\r k)(2\r i + 0\r j - \r k)]](https://tex.z-dn.net/?f=%3D%20%5B%28-420%5Cr%20i%20%2B0%5Cr%20j%20%2B210%5Cr%20k%29%282%5Cr%20%20i%20%2B%200%5Cr%20j%20-%20%5Cr%20k%29%5D)



The amount of workdone by Jill would be

![= [(180 \r i + 0\r j + 360\r k)(2\r i +0\r j -\r k)]](https://tex.z-dn.net/?f=%3D%20%5B%28180%20%5Cr%20i%20%2B%200%5Cr%20j%20%2B%20360%5Cr%20k%29%282%5Cr%20i%20%2B0%5Cr%20j%20-%5Cr%20k%29%5D)


According to work energy theorem the Workdone is equal to the kinetic energy of the boat
![W = K.E = \frac{1}{2} m *[v^2 - (1.1)^2]](https://tex.z-dn.net/?f=W%20%3D%20K.E%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20m%20%2A%5Bv%5E2%20-%20%281.1%29%5E2%5D)
![-1050 = 0.5*3300 [*v^2- (1.1)^2]](https://tex.z-dn.net/?f=-1050%20%20%3D%200.5%2A3300%20%5B%2Av%5E2-%20%281.1%29%5E2%5D)
![-1050 = 1650 [v^2 -1.21]](https://tex.z-dn.net/?f=-1050%20%3D%201650%20%5Bv%5E2%20-1.21%5D)



