(a). The power of the candy bar is,

The time taken to play on 800 kJ energy of the candy bar is,

where E is the energy.
Substituting the known values,

As 1 minute is equal to 60 seconds,
Thus,

Thus, the time taken to play tennis on the 800 kJ energy is 30.3 minutes.
(b). By doing the exercise, the process of digestion of food inside our body increases. Thus, the exercise does not helps us to burn the calories. But it helps us to diggest the heavy meal like candy bar easily.
The time taken to digest the canndy bar or to utilise its energy is large because it takes a lot of time to burn small amount of food and make it digest quickly.
No deaf children dont. im deaf and i dident go through those stages.
For this problem, we use the Coulomb's Law. The working equation is written below:
F = kQ₁Q₂/d²
where
F is the electric force
k is a constant equal to 8.99 × 10⁹ N • m²/C²
Q is the charges for the two objects
d is he distance between the objects
Substituting the values,
F = (8.99 × 10⁹ N • m²/C²)(-15×10⁻⁶ C)(-11×10⁻⁶ C)/(180²)
F = 4.578×10⁻⁵ N
Next, we determine the gravitational force using the Law of Universal Gravitation:
F = Gm₁m₂/d²
where
F is the gravitational force
G is a constant equal to 6.67 × 10⁻¹¹ N • m²/kg²
m is the masses of the objects
d is the distance between the objects
F = (6.67 × 10⁻¹¹ N • m²/kg²)(58,000 kg)(52,000 kg)/(180²)
F = 6.2089×10⁻⁶ N
The sum of the two forces equal the net force:
Net force = 4.578×10⁻⁵ N + 6.2089×10⁻⁶ N = 1.079×10⁻⁵ N
Answer:
t = 25.5 min
Explanation:
To know how many minutes does Richard save, you first calculate the time that Richard takes with both velocities v1 = 65mph and v2 = 80mph.

Next, you calculate the difference between both times t1 and t2:

This is the time that Richard saves when he drives with a speed of 80mph. Finally, you convert the result to minutes:

hence, Richard saves 25.5 min (25 min and 30 s) when he drives with a speed of 80mph