If energy is conserved, why do people get tired , and why are we running short on “energy supplies?”
1 answer:
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Answer:
u = 3.35 m/s
Explanation:
given,
mass , m = 0.455 kg
R = 0.675 m
Height of Loop = 1.021 m
the speed required at the top of loop be v
equating the force vertically
v² = 6.622
v = 2.57 m/s
Let the initial speed of ball be u
using conservation of energy
where,
0.7 u² = 7.85092
u² = 11.2156
u = 3.35 m/s
the initial speed is 3.35 m/s
Answer:
R = 4.24 x 10⁻⁴ m
Explanation:
given,
mass of the person = 60.3-kg
mass of the bullet = 10 gram = 0.01 Kg
velocity of bullet = 389 m/s
angle made with the horizontal = 45°
using conservation of momentum.
M v + m u = ( M + m ) V
60.3 x 0 + 0.01 x 389 = (60.3 + 0.01) V
V = 0.0645 m/s
for calculation of range
R = 4.24 x 10⁻⁴ m
the distance actor fall is R = 4.24 x 10⁻⁴ m
Answer:
Constant speed: yes
Constant velocity: no
Explanation:
Let's remind the definition of speed and velocity:
- Speed is a scalar quantity, which is equal to the ratio between the distance covered (regardless of the direction) and the time taken:
- Velocity is a vector quantity, so it has both a magnitude and a direction. The magnitude is equal to the rate between the displacement of the object and the time taken, while the direction is the same as the displacement.
In this problem, we notice that:
- The speed of the car remains constant, as it is 90 km/h
- However, its direction of motion changes while the car travels round the corner: this means that the direction of the velocity is also changing, therefore velocity is not constant.