First you need to make a difference between friction while object is stationary and the friction while object is moving. Force required to start moving some object is slightly greater than force required to maintain objects movement. That means that to move a chair you need some force F1 but you can than slightly reduce force and chair will still be moving.
Now to the problem in this question: It can be said that "stationary friction force" is equal to 15 Newtons. Its also good to know that friction force between chair and floor while you are increasing your push is also increasing and is equal to force of your push. Once it reaches 15N which is it "critical value" for that chair, chair starts moving and friction force drops a little bit and now it is called friction force of moving chair.
Answer:
the girl's displacement in both magnitude and direction is 7.81 m at 50.2⁰ North west.
Explanation:
Given;
6km due west, and
5km due north
The magnitude of her displacement is calculated by forming a right angled triangle. The hypotenuse side of the triangle is the girl's displacement.
d² = 5² + 6²
d² = 25 + 36
d² = 61
d = √61
d = 7.81 m
The direction of the girl is calculated as;
Therefore, the girl's displacement in both magnitude and direction is 7.81 m at 50.2⁰ North west.
Answer:
500km/h
Explanation:
I don't know what units you need the answer in, but if the units were to stay the same, then that's the answer^.
Aaron's car is moving at speed of 30 m/s
His reaction time is given as 0.7 s
but when he is tired the reaction time is doubled
Now we need to find the distance covered by his car when he is tired during the time when he react to apply brakes
So here since during this time speed is given as constant so we can say that distance covered can be product of speed and time
So here we can use
So the car will move to 42 m during the time when he apply brakes
Answer:
This is because white light consists of 7 colours with different angles o deviation or retraction.
Explanation:
When a narrow beam of light is refracted by a prism the light spreads into a band of colours (called the spectrum of light )
But in this case if a blue colour is observed it is due to the angle of refraction ,for instance red is refracted the least and hence is seen
