Displacement s = (u+v)*t/2 (t refers to delta time)
= (0.45 + 2.7)*6/2
= 3.15*3
= 9.45 m
Answer:
The railroad tracks are 13 m above the windshield (12 m without intermediate rounding).
Explanation:
First, let´s calculate the time it took the driver to travel the 27 m to the point of impact.
The equation for the position of the car is:
x = v · t
Where
x = position at time t
v = velocity
t = time
x = v · t
27 m = 17 m/s · t
27 m / 17 m/s = t
t = 1.6 s
Now let´s calculate the distance traveled by the bolt in that time. Let´s place the origin of the frame of reference at the height of the windshield:
The position of the bolt will be:
y = y0 + 1/2 · g · t²
Where
y = height of the bolt at time t
y0 = initial height of the bolt
g = acceleration due to gravity
t = time
Since the origin of the frame of reference is located at the windshield, at time 1.6 s the height of the bolt will be 0 m (impact on the windshield). Then, we can calculate the initial height of the bolt which is the height of the railroad tracks above the windshield:
y = y0 + 1/2 · g · t²
0 = y0 -1/2 · 9.8 m/s² · (1.6 s)²
y0 = 13 m
Answer:
Explanation:
1. We use the conservation of momentum for before the raining and after. And also we take into account that in 0.5h the accumulated water is
100kg/h*0.5h = 50kg
2. the momentum does not conserve because the drag force of water makes that the boat loses velocity
3. If we assume that the force of the boat before the raining is
where we have assumed that the acceleration of the boat is 1m/s{2} just before the rain starts
And if we take the net force as
where we take v=1m/s because we are taking into account tha velocity just after the rain stars.
I hope this is useful for you
regards
<span>A baseball speeds up as it falls through the air.
Yes. Forces on the balloon are unbalanced.
The balloon is speeding up, so we know that the downward force
of gravity is stronger than the upward force of air resistance.
A soccer ball is at rest on the ground.
No. The ball is not accelerating, so we know that the forces on it
are balanced.
The downward force of gravity on the ball and the upward force
of the ground are equal.
An ice skater glides in a straight line at a constant speed.
No. The skater's speed and direction are not changing, so he is not
accelerating. That tells us that the forces on him are balanced.
A bumper car hit by another car moves off at an angle.
Yes. The direction in which the car was moving changed.
That's acceleration, so we know that the forces on it are unbalanced,
at least at the moment of impact.
A balloon flies across the room when the air is released.
Yes. The balloon was not moving. But when the little nozzle was
opened, it started to zip around the room. So its speed changed.
And, as it goes bloozing around the room, its direction keeps changing too.
There's a whole lot of acceleration going on, so we know the forces on it
are unbalanced.</span>
Answer: Skilled manpower is essential to carry out several development activities.
Explanation:
