Explanation:
It is given that,
Initially the car is at rest and travels for t₁ seconds with a uniform acceleration a₁. The driver then applies the brakes, causing a uniform acceleration a₂, If the brakes are applied for t₂ seconds.
We need to find the speed of the car just before the beginning of the braking period.
Using the formula of acceleration. It is given by :
u = 0
So, just before the beginning of the braking period the speed of the car is . Hence, this is the required solution.
Answer:
<em>Explanation below</em>
Explanation:
<u>Speed vs Velocity </u>
These are two similar physical concepts. They only differ in the fact that the velocity is vectorial, i.e. having magnitude and direction, and the speed is scalar, just the magnitude regardless of the direction. They are strongly related to the concepts of displacement and distance, which are the vectorial and scalar versions of the space traveled by a moving object. The velocity can be computed as
Where is the position vector and t is the time. The speed is
To compute , we only need to know the initial and final positions and subtract them. To compute d, we need to add all the distances traveled by the object, regardless of their directions.
Maggie walks to a friend's house, located 1500 meters from her place. The initial position is 0 and the final position is 1500 m. The displacement is
and the velocity is
Now, we know Maggie had to make three different turns of direction to finally get there. This means her distance is more than 1500 m. Let's say she walked 500 m in all the turns, then the distance is
If she took the same time to reach her destiny, she would have to run faster, because her average speed is