Answer: 24.7 km/h
Explanation:
1) Average speed definition and formula
The average speed is the total distance run divided by the time elapsed:
S = distance / time
2) Distance 1 = 67 km
3) Distance 2 = 81 km
4) Total distance traveled = 67 km + 81 km = 148 km
5) time 1 = 1 hour
6) time 2 = 5 hours
7) total time = time 1 + time 2 = 1 h + 5 h = 6 h
8) Average speed:
S = 148 km / 6 h = 24.7 km/h
Answer:
<em>113.4 J</em>
Explanation:
<u>Elastic Potential Energy</u>
Is the energy stored in an elastic material like a spring of constant k, in which case the energy is proportional to the square of the change of length Δx and the constant k.

The spring has a natural length of 0.7 m and a spring constant of k=70 N/m. When the spring is stretched to a length of 2.5 m, the change of length is
Δx = 2.5 m - 0.7 m = 1.8 m
The energy stored in the spring is:

PE = 113.4 J
The angular speed of the device is 1.03 rad/s.
<h3>What is the conservation of angular momentum?</h3>
A spinning system's ability to conserve angular momentum ensures that its spin will not change until it is subjected to an external torque; to put it another way, the rotation's speed will not change as long as the net torque is zero.
Using the conservation of angular momentum

Here, = the system's angular momentum before the collision
= 0 + mv
= (0.005)(450)(0.752)
= 1.692 kgm²/s
The moment of inertia of the system is given by
I = 2(M₁R₁² + M₂R₂²)+ mR₁²
= 2[(1.2)(0.8)² +(0.5)(0.3)²]+0.005(0.8)²
= 1.6292 kgm²
Here, = Iω
So,
1.692 = 1.6292(ω)
ω = 1.03 rad/s
To know more about the conservation of angular momentum, visit:
brainly.com/question/1597483
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Answer:
14.36m/s
Explanation:
From the law of conservation of linear momentum
m1u1 + m2u2 = v(m1 + m2)
68×17 + 76×12= v(68+76)
1156+912 = 144v
2068 = 144v
v = 2068/144
=14.36 m/s