Answer:
t = 4.468 h
Explanation:
For this exercise let's start by calculating the distance where the boat is
the first trip is 50 miles at 45 °, then 90 miles at 80 °,
to find the total distance let's find the distance of each displacement
cos 45 = x₁ / 50
sin 45 = y₁ / 50
x₁ = 50 cos 45 = 35.35 miles
y₁ = 50 cos 45 = 35.35 miles
cos 80 = x₂ / 90
sin 80 = y₂ / 90
x₂ = 90 cos 80 = 15.63 miles
y₂ = 90 sin 80 = 88.63 miles
let's find the total displacement in each axis
x_total = x₁ + x₂
x_total = 35.35 + 15.63
x_total = 50.98 miles
y_total = y₁ + y₂
y_total = 35.35 + 88.63
y_total = 123.98 miles
Let's use the Pythagorean theorem to find the modulus of the displacement
R = √ (x_total² + y_total²)
R = √ (50.98² + 123.98²)
R = 134.05 miles
The boat goes at a constant speed,
v = R / t
t = R / v
let's calculate
t = 134.05 / 30
t = 4.468 h
Answer:
17.63W
Explanation:
The total energy supplied to the ice is used to melt the ice. Since the ice starts to melt at
and also melts completely at the same temperature, the latent heat of fusion will be the focus in solving this problem.
Latent heat of fusion
is defined as the amount of energy that changes a solid substance to liquid state without any change in temperature. It is given by the following relationship;
![H_f=ml.....................(1)](https://tex.z-dn.net/?f=H_f%3Dml.....................%281%29)
where m is the mass of the substance and l is the specific latent heat of fusion of the substance.
The specific latent heat of fusion of ice is
approximately.
The total heat supplied to the ice was used to melt the ice and is calculated using equation (1), given that m = 4.56kg.
![H_f=4.56*334000\\H_f=1523040J](https://tex.z-dn.net/?f=H_f%3D4.56%2A334000%5C%5CH_f%3D1523040J)
The total energy supplied to the ice is equivalent to the average power P entering the ice multiplied by the time t for which the power is supplied. Therefore;
![P *t=1523040..............(2)](https://tex.z-dn.net/?f=P%20%2At%3D1523040..............%282%29)
where t = 1 day and 1 day = 24 hours.
24 hours = 60 x 60 x 24s =86400s.
Hence, t = 86400s.
Substituting into equation (2), we get the following;
![P*86400=1523040](https://tex.z-dn.net/?f=P%2A86400%3D1523040)
![P=\frac{1523040}{86400}\\P=17.63W](https://tex.z-dn.net/?f=P%3D%5Cfrac%7B1523040%7D%7B86400%7D%5C%5CP%3D17.63W)
<h2>
Option A is the correct answer.</h2>
Explanation:
Here velocity of ball and bat are in opposite direction.
Velocity of ball = 40 m/s
Velocity of bat = 18 m/s
Since they are in opposite direction relative velocity is given by,
Relative velocity = 40 + 18 = 58 m/s
Distance to home plate = 18 m
We have
Displacement = Velocity x Time
18 = 58 x Time
Time = 0.3 seconds
Option A is the correct answer.
Explanation:
VELOCITY: BECAUSE ITS A VECTOR QUANTITY