Answer:
163.33 Watts
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 40 Kg
Height (h) = 25 m
Time (t) = 1 min
Power (P) =..?
Next, we shall determine the energy. This can be obtained as follow:
Mass (m) = 40 Kg
Height (h) = 25 m
Acceleration due to gravity (g) = 9.8 m/s²
Energy (E) =?
E = mgh
E = 40 × 9.8 × 255
E = 9800 J
Finally, we shall determine the power. This can be obtained as illustrated below:
Time (t) = 1 min = 60 s
Energy (E) = 9800 J
Power (P) =?
P = E/t
P = 9800 / 60
P = 163.33 Watts
Thus, the power required is 163.33 Watts
The height to which the weight-watcher must climb to work off the equivalent 991 (food) Calories is 0.59 Km
<h3>How to determine the energy. </h3>
1 food calorie = 103 calories
Therefore,
991 food calories = 991 × 103
991 food calories = 102073 calories
Multiply by 4.2 to express in joule (J)
991 food calories = 102073 × 4.2
991 food calories = 428706.6 J
<h3>How to determine the height </h3>
- Energy (E) = 428706.6 J
- Mass (m) = 73.9 kg
- Acceleration due to gravity (g) = 9.8 m/s²
E = mgh
Divide both side by mg
h = E / mg
h = 428706.6 / (73.9 × 9.8)
h = 591.95 m
Divide by 1000 to express in km
h = 591.95 / 1000
h = 0.59 Km
Learn more about energy:
brainly.com/question/10703928
To stop the car it would be 100m because if the car is going to 65km/h then it would still be 100km/h
Let's break the question into two parts:
1) The force needed in Ramp scenario.
2) The effort force needed in the lever scenario.
1. Ramp Scenario: In an incline, the only component of cart's weight(
mg) that is in the direction of motion is
. Therefore the effort force in this case must be equal or greater than
.
Now we need to find

.

is the angle between the incline of the ramp and the ground.
Since the height is
5m and the length of the ramp is
8m, 
would be
5/8 or 0.625. Now that you have

, mutiple it with
mg.
=> m*g*

= 20 * 10 * 5 / 8. (Taking g = 10 m/s² for simplicity) = 125N
Therefore, the minimum Effort force you would require in this case is
125N.
2. Lever Scenario:
Just apply "moment action" in this case, which is:


= ?

= mg = 20 * 10 = 200N

= 10m

= 1m
Plug-in the values in the above equation:

= 200/10=
20NAs 20N << 125N, the best choice is to use lever.