Answer:
Ec = 6220.56 kcal
Explanation:
In order to calculate the amount of Calories needed by the climber, you first have to calculate the work done by the climber against the gravitational force.
You use the following formula:
(1)
Wc: work done by the climber
g: gravitational constant = 9.8 m/s^2
M: mass of the climber = 78.4 kg
h: height reached by the climber = 5.42km = 5420 m
You replace in the equation (1):
(2)
Next, you use the fact that only 16.0% of the chemical energy is convert to mechanical energy. The energy calculated in the equation (2) is equivalent to the mechanical energy of the climber. Then, you have the following relation for the Calories needed:
Ec: Calories
You solve for Ec and convert the result to Cal:
The amount of Calories needed by the climber was 6220.56 kcal
Answer:
thanks for the five points
-- pass the light through a lens
The path of the light is bent (refracted) to a new direction.
-- bounce the light off a shiny surface
The light is sent back (reflected) in the direction from which it arrived.
-- pass the light through a prism
The light is spread out according to the different wavelengths
that may be in it.
-- put something black in the light's path
The light is completely absorbed and is never seen again.
-- turn the light off
The source stops emitting light.
-- throw a towel over the lamp
The light is absorbed in the towel, and not seen outside of it.
Answer:
V = 6 m/s
Explanation:
Given that,
Initial speed of an object is 20 m/s
Final speed of an object is 10 m/s
Time, t = 5 s
We need to find the average speed of the object during these 5 seconds. Let it is equal to V. Here, time is same. The average speed is given by :
So, the average speed of the object is 6 m/s.
