Answer:the witch has nothing to do with the problem
Explanation:
A large force is required to accelerate the mass of the bicycle and rider. Once the desired constant velocity is reached, a much smaller force is sufficient to overcome the ever-present frictional forces.
The correct answer is:
<span>C) The actual frequency of the siren does not change despite appearances.
In fact, Bob will observe an increase in the apparent frequency as the emergency vehicle approaches him, while Jill will observe a decrease in the apparent frequency as the emergency vehicle moves away from him, because of the Doppler effect (the relative velocity between the observer and the source of the sound is changing), but this effect involves the apparent frequency, while the real frequency of the siren will remain the same.</span>
Answer: b. Throw it directly away from the space station.
Explanation:
According to <u>Newton's third law of motion</u>, <em>when two bodies interact between them, appear equal forces and opposite senses in each of them.</em>
To understand it better:
Each time a body or object exerts a force on a second body or object, it (the second body) will exert a force of equal magnitude but in the opposite direction on the first.
So, if the astronaut throws the wrench away from the space station (in the opposite direction of the space station), according to Newton's third law, she will be automatically moving towards the station and be safe.
Answer:
The distance between the two objects must be squared.
Explanation:
Gravitational force always act between two objects that have mass. The gravitational force is a weak force and attractive in nature.
The force of pull depends on the masses of the two objects and the distance between them.
The formula to calculate gravitational force between two objects having masses 'm' and 'M' and separated by a distance 'd' is given as:
Where, 'G' is called the universal gravitational constant and its value is equal to 
.
Now, from the above formula, it is clear that, the force of gravitation is inversely proportional to the square of the distance between the two objects.
Thus, the quantity that must be squared in the equation of gravitational force between two objects is the distance 'd'.
