Answer:
we assume that it starts with a velocity of 10m/s. At 2m height above ground level, its velocity decreases at 3m above ground level
for its way down the velocity at 3m on its way down is more than its velocity at 2m on its way down.
Explanation:
A student throws a small rock straight upwards. The rock rises to its highest point and then falls back down. How does the speed of the rock at 2m on the way down compare with its speed at 2m on the way up?
It decreases in speed on its way down and increases in speed on its way down.
it decreases in speed on its way up because the the vertical motion is against the earths gravitational pull on an object to the earth's center
.It increases in speed on his way down because its under the influence of gravity
from newton's equation of motion we can check by
using V^2=u^2+2as
we assume that it starts with a velocity of 10m/s. At 2m height above ground level, its velocity decreases at 3m above ground level
for its way down the velocity at 3m on its way down is more than its velocity at 2m on its way down.
Answer:
The new kinetic energy would be 16 times greater than before.
Explanation:
Kinetic energy is found using this formula:
- KE = 1/2mv²
- where KE = kinetic energy (J), m = mass (kg), and v = velocity (m/s)
We can see that kinetic energy is directly proportional to the square of the velocity, meaning that if the speed was increased by 4 times, then the kinetic energy would get increased by a factor of 16.
The velocity just before the ball hits the ground can be found by the equation:
Let's substitute h = 10 m and h = 40 m into this formula.
We can see that the velocity increases by a factor of 4 (10 m → 40 m).
Therefore, this means that the kinetic energy would also be increased by a factor of (4)² = 16. Thus, the answer is D) The new kinetic energy would be 16 times greater than before.
Answer: Average acceleration is -2.407 
Explanation:
Average acceleration is equal to change in velocity divided by time taken
therefore, 
=> 
The first sentence got me all psyched up to answer the question "What
horizontal force do the engines generate in order to accelerate it ?".
But the actual question, in the second sentence, turned out to be
a completely different one.
When the plane levels off and continues on at a constant altitude, it's
not accelerating up or down, so the net vertical force on it is zero.
The lift generated by the wings is exactly balancing the downward
force of gravity on the airplane.
