Answer:
c
Explanation:
the question answered itself.
Explanation:
The formula we are going to use is
Pressure = F/A
Elephant:
First, we need to convert weight into newtons.
1kg=9.8 newtons, so 2800kg × newtons = 27440newtons
For 4 feet= 200×4= 800cm^2
Convert the area to meter squared using the following:
1 centimeter squared = 0.0001 meters squared
800cm^2×0.0001= 0.08m^2
Pressure=F/A
Pressure= 27440/0.08
The pressure exerted on the ground by the elephant is 343000 Pascals.
Vulture:
12kg×9.8=117.6newtons
for 2 feet= 2.0×2=4cm^2
4×0.0001=0.0004m^2
117.6/0.0004= 294000 Pascals
To compare the pressure, just do a ratio of the elephant's pressure to vulture's pressure.
343000/294000≈ 1.17
So the pressure is about 1 times bigger.
Keep in mind that the elephant has 4 feet, which help to increase the area which in turn decrease the pressure.
When it leaves the hand, it's rising at 18.2 m/s. After 1 second, gravity has slowed it to (18.2 - 9.8) = 8.4 m/s, still rising. Its average speed during the first second is 1/2 of (18.2 + 8.4) = 13.3 m/s. Rising for 1 second at an average speed of 13.3 m/s, it rises 13.3m from the hand.
The correct answer is
A. The mechanical energy transforms to thermal energy as the pendulum slows and eventually stops moving.
In fact, we must keep in mind the presence of the air, which causes some resistance to the motion of the pendulum. As the pendulum moves through the air, part of its mechanical energy is transferred to the molecules of air because of the friction of this molecules with the surface of the pendulum. As a result, the pendulum slows down, and eventually stops. The initial energy of the pendulum has been converted into thermal energy of the molecules of air, which move faster now.
This does not represent acceleration, it represents CONSTANT VELOCITY