Answer:
261.3 m/s
Explanation:
Mass of bullet=m=15 g=
1 kg=1000g
Mass of block=M=3 kg
d=0.086 m
Total mass =M+m=3+0.015=3.015 kg
K.E at the time strike=Gravitational potential energy at the end of swing

Using g=
Substitute the values




Velocity after collision=V=1.3 m/s
Velocity of block=v'=0
Using conservation law of momentum

Using the formula




The mechanical energy of the girl will be conserved because the system is isolated and the initial potential energy will be equal to final kinetic energy.
<h3>
What is the law of conservation of energy?</h3>
The law of conservation of energy states that energy can neither be created nor destroyed but can be transformed from one form to another.
The change in the potential energy of the launched from a height into the pool without friction from the given height h is calculated by applying the following kinematic equation.
ΔP.E = ΔK.E
where;
- ΔP.E is change in potential energy of the child
- ΔK.E is change in the kinetic energy of the child
mghf - mghi = ¹/₂mv² - ¹/₂mu²
where;
- m is the mass of the girl
- g is acceleration due to gravity
- hi is the initial height of the girl
- hf is the final height when she is launched into the pool
- u is the initial velocity
- v is the final velocity of the girl
Thus, for every closed or isolated system such as this case, mechanical energy is always conserved because the initial potential energy of the girl will be converted into her final kinetic energy.
Learn more about conservation of mechanical energy here: brainly.com/question/332163
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<span>The work output of a machine divided by the work input is the "Efficiency" of the machine.
Hope this helps!</span>
Answer:
A. 69.9m
Explanation:
Given parameters:
Initial velocity = 10.5m/s
Final velocity = 21.7m/s
Time = 4.34s
Unknown:
Distance traveled = ?
Solution:
Let us first find the acceleration of the car;
Acceleration =
v is final velocity
u is initial velocity
t is the time
Acceleration =
= 2.58m/s²
Distance traveled;
V² = U² + 2aS
21.7² = 10.5² + 2 x 2.58 x S
360.64 = 2 x 2.58 x S
S = 69.9m