Answer:
a = 2 [m/s²]
Explanation:
To be able to solve this problem we must make it clear that the starting point when the time is equal to zero, the velocity is 5 [m/s] and when three seconds have passed the velocity is 11 [m/s], this point is the final point or the final velocity.
We can use the following equation.
where:
Vf = final velocity = 11 [m/s]
Vo = initial velocity = 5 [m/s]
a = acceleration [m/s²]
t = time = 3 [s]
Let the rescue boat starts at an angle theta with the North
now its velocity towards East is given as
now in some time "t" it will catch the boy
so we will have
also we have
now we have
by solving above we got
Answer:
D) Acceleration is positive and increasing.
Explanation:
Acceleration is defined as the rate of change of velocity per unit time; in formulas:
where is the variation of velocity and
is the variation in time.
The graph shows the velocity vs the time of a moving object. We can see that is the increment on the y-axis, while
is the increment on the x axis: therefore, the ratio
is the slope of the curve. In fact, in a velocity-time graph, the slope of the curve corresponds to the acceleration of the object.
In this particular graph, we see that the slope of the curve continues to increase: therefore, the acceleration is positive (because the slope is positive, since the velocity is increasing) and increasing (because the slope is increasing).