(a)
Final speed of the sled and driver relative to the ground.
(a)
Answer to Problem 75PQ
The final speed of the sled and driver relative to the ground is
Explanation of Solution
Apply law of conservation of momentum to the system. The momentum of combination of sled, backpack and driver is equal to the momentum of backpack plus the momentum of sled and driver.
Write the equation to find the combined momentum of backpack, driver and sled.
Here,
After some time harness of the sled breaks. In order to stop the harness the driver throws away his back pack in the opposite direction of motion of sled. Thus the final momentum of system is equal to the sum of momentum of back pack plus the momentum of driver and sled.
Write the equation to find the momentum after the breakage of harness.
Here,
Apply conservation of momentum.
Substitute (II) and (I) in (III).
The relative velocity of back pack with respect to the sled is equal to the sum of velocity of sled and velocity of back pack.
Write the equation to find the relative speed of back pack with respect to the sled.
Here,
Rearrange equation (V) to find
Substitute
Simplify equation (VII) to get
Conclusion:
Substitute
Therefore substitute
Therefore, the final speed of the sled and driver relative to the ground is
(b)
Final speed of the back pack with respect to the ground.
(b)
Answer to Problem 75PQ
The final speed of back pack with respect to the ground is
Explanation of Solution
Write the equation to find the
Conclusion:
Substitute
Therefore, final speed of the back pack with respect to the ground is
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Chapter 10 Solutions
Physics for Scientists and Engineers: Foundations and Connections
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