A)After 3,5s -->v=v0+gt=21+(-9,8•3,5)=21+(-34,3)=-13,3m/s;
b)The maximum height that the orange reaches is h max=v0^2/2g=22,5m;v^2=sqrt(2gh)=>h=v^2/2g=9,025m.The height of the orange is H=h max-h=13,475m.;
c)The orange is traveling down.
Gravitational forces are stronger over shorter distances, and
weaker over longer distances. That's a big part of the reason
why our bodies are attracted to the Earth with more force than
we're attracted to Jupiter, for example.
The force doesn't just get weaker in proportion to the distance.
It gets weaker in proportion to the SQUARE of the distance.
Answer:2 amperes
Explanation:
Voltage=120v
Total resistance=15+15+30
Total resistance=60 ohms
Current=voltage ➗ resistance
Current=120 ➗ 60
Current=2 amperes
“The mechanical energy is conserved" in the given system is true out of all given options.
Answer: Option 2
<u>Explanation:
</u>
According to law of conservation of energy, the energy will neither be created nor be destroyed, irrespective of the type of energy. As in the present case, the ball is bowled and it is travelling to ground, so the mechanical energy is working in this case. Thus the mechanical energy will be conserved. Even it can be shown as follows.
As the 2 kg ball is travelling with a speed of 7 m/s, the kinetic energy exhibited by the ball while falling to ground will be
Thus, applying given values, we get,
Similarly, as the ball is 2.5 m above ground, the potential energy will also be exhibited by the ball at that position. So the potential energy will be
Thus,
Thus as the magnitude of kinetic energy is equal to the magnitude of potential energy exhibited by the ball with varying direction, the net energy will be zero. This is because the kinetic energy will be acting in opposite direction to the potential energy exhibited by the ball. Hence as the net energy is zero, the mechanical energy is conserved.