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

The net force acting on the block is ~


So, the Answer in the boxes will be ~

Answer:
option (c)
Explanation:
When an object thrown upwards, the value of acceleration acting on the object is acceleration due to gravity which is always acting towards the earth.
As it falls downwards, the acceleration is again equal to the acceleration due to gravity.
So, the ball's acceleration is constant.