Answer:
The plane would need to travel at least
(
.)
The
runway should be sufficient.
Explanation:
Convert unit of the the take-off velocity of this plane to
:
.
Initial velocity of the plane:
.
Take-off velocity of the plane
.
Let
denote the distance that the plane travelled along the runway. Since acceleration is constant but unknown, make use of the SUVAT equation
.
Notice that this equation does not require the value of acceleration. Rather, this equation make use of the fact that the distance travelled (under constant acceleration) is equal to duration
times average velocity
.
The distance that the plane need to cover would be:
.
Answer:

Explanation:
<u>Accelerated Motion
</u>
When a body changes its speed at a constant rate, i.e. same changes take same times, then it has a constant acceleration. The acceleration can be positive or negative. In the first case, the speed increases, and in the second time, the speed lowers until it eventually stops. The equation for the speed vf at any time t is given by

where a is the acceleration, and vo is the initial speed
.
The train has two different types of motion. It first starts from rest and has a constant acceleration of
for 182 seconds. Then it brakes with a constant acceleration of
until it comes to a stop. We need to find the total distance traveled.
The equation for the distance is

Our data is

Let's compute the first distance X1


Now, we find the speed at the end of the first period of time


That is the speed the train is at the moment it starts to brake. We need to compute the time needed to stop the train, that is, to make vf=0



Computing the second distance


The total distance is



Answer: B
Explanation:
It's not the time it took to heat the substance, so that rules out A and C.
This means that we only have to choose between
B. the area of contact
D. the area of the substances
(since everything else in each of those answers are the same)
Area of contact matters more (e.g. an object with greater surface area is exposed to the air more, will lose/gain heat quicker than an object with less surface area).
Increase in height can cause climber's gravitational potential energy greater than any other mean
Hope this helps!