Answer:
the energy of the spring at the start is 400 J.
Explanation:
Given;
mass of the box, m = 8.0 kg
final speed of the box, v = 10 m/s
Apply the principle of conservation of energy to determine the energy of the spring at the start;
Final Kinetic energy of the box = initial elastic potential energy of the spring
K.E = Ux
¹/₂mv² = Ux
¹/₂ x 8 x 10² = Ux
400 J = Ux
Therefore, the energy of the spring at the start is 400 J.
Distance = speed x time
distance = 116 x 10
distance = 1160 m
No i took the test and the answer is actually homogenous mixture
My guess for this one would be; 400 N
My reasoning would be; it starts at 0 on both X and Y, if you need to get to 1.00 meters thats 4/4. 1/4 of 1.00 is .25, and on .25 its on 100 so multiply it by 4 to make 1.00 and you get 400 N
Answer:
The speed of the raft is 1.05 m/s
Explanation:
The equation for the position of the stone is as follows:
y = y0 + v0 · t + 1/2 · g · t²
Where:
y = height of the stone at time t
y0 = initial height
v0 = initial speed
t = time
g = acceleration due to gravity
The equation for the position of the raft is as follows:
x = x0 + v · t
Where:
x = position of the raft at time t
x0 = initial position
v = velocity
t = time
To find the speed of the raft, we have to know how much time the raft traveled until the stone reached the river. For that, we can calculate the time of free fall of the stone:
y = y0 + v0 · t + 1/2 · g · t² (v0=0 because the stone is dropped from rest)
If we place the origin of the frame of reference at the river below the bridge:
0 m = 95.6 m - 9.8 m/s² · t²
-95.6 m / -9,8 m/s² = t²
t = 3.12 s
We know that the raft traveled (4.84 m - 1.56 m) 3.28 m in that time, then the velocity of the raft will be:
x/t = v
3.28 m / 3.12 s = v
v = 1.05 m/s
