#82
here we know that
acceleration = 2 m/s/s
time = 5 s
initial speed = 4 m/s
now we can use kinematics to find the final speed
So correct answer will be option D)
#83
here we know that
acceleration = 3 m/s/s
time = 4 s
initial speed = 5 m/s
now we can use kinematics to find the final speed
So correct answer will be option C)
#84
here we know that
acceleration = 7 m/s/s
time = 3 s
initial speed = 8 m/s
now we can use kinematics to find the final speed
So correct answer will be option C)
Answer:
v = 15.65 m/s
Explanation:
We use conservation of mechanical energy between initial (i) and final (f) states:
Pi + KEi = Pf + KEf
At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.
Pi = m g h = 600 J
and the KEi = 0 J (no velocity)
Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:
m = 600 J / (g 12.5) = 4.9 kg
Using conservation of mechanical energy, the final state is:
Pf + KEf = 600 J
with Pf = 0 (just touching the ground)
KEf= 1/2 4.9 (v^2)
and we solve for the velocity:
600 J = 0 + 1/2 4.9 (v^2)
v^2 = 600 * 2 / 4.9 = 244.9
v = 15.65 m/s
Answer:
3675 J
Explanation:
Gravitational Potential Energy = 
× mass × g × height
( g is the gravitation field strength )
Mass = 50 kg
G = 9.8 N/kg ( this is always the same )
Height = 15 m
Gravitational Potential Energy = × 50 ×9.8 × 15
= 3675 J
Answer: The scientist gives up and starts an investigation on a new topic.
Explanation:
The data is altered so that it supports the original hypothesized. The data is then altered so that it supports the original hypothesis.
