Answer:
h = 1.94 m
Explanation:
When the bull dog and skate board reach the bottom of the well, all of its potential energy is converted to the kinetic energy:
Kinetic Energy Gained by Bull Dog and Skate Board = Potential Energy Lost by Bull Dog and Skate Board
K.E = P.E
K.E = mgh
h = K.E/mg
where,
h = depth of well = ?
K.E = Kinetic Energy at bottom = 380 J
m = mass of bull dog and skate board = 20 kg
g = 9.8 m/s²
Therefore,
h = 380 J/(20 kg)(9.8 m/s²)
<u>h = 1.94 m</u>
Answer: D(t)= 50(4/5)^t
Explanation: If 1/5 of the temperature difference is lost each minute, that means 4/5 of the difference remains each minute. So each minute, the temperature difference is multiplied by a factor of 4/5 (or 0.8).
If we start with the initial temperature difference, 50° Celsius, and keep multiplying by 4/5, this function gives us the temperature difference t minutes after the cake was put in the cooler.
Answer:
50.09 km/h
Explanation:
Given that an airplane flying due north at 90 km/h is being blown due west. The planes total velocity is 103 km/ hr north west.
What is velocity of the wind ?
The wind velocity can be calculated by using pythagorean theorem.
From the question,
Resultant Velocity R = 103 km/h
Plane velocity P = 90 km/h
Wind velocity W = ?
W^2 = R^2 - P^2
Substitutes all the parameters into the formula
W^2 = 103^2 - 90^2
W^2 = 10609 - 8100
W^2 = 2509
W = sqrt ( 2509 )
W = 50.09 km/h
Therefore, the velocity of the wind is 50.09 km/h
Answer:
15.8 seconds
Explanation:
Create an extended calculation to convert all the unit to what you need.
160 km 1000 m 1 hour 1 min
----------- x ------------- x -------------- x ---------- = 44.4 m/s
1 hour 1 km 60 min 60 sec
So 160km/hr is equal to 44.4m/s
Now you can figure out how many seconds it will take to go 700 meters.
44.4 m
---------- X x sec = 700 m
1 sec
Solve for x sec
x sec = 700m / 44.4 m/s
= 15.8 seconds