Question

Sheila weighs 60 kg and is riding a bike. Her momentum on the bike is 340 kg • m/s. The bike hits a rock, which stops it completely and throws Sheila forward onto the pavement. If there is no net force on the system, what is Sheila’s velocity immediately after she is thrown from the bike?

Answer 1

Answer:

5.7 m/s     

Explanation:

The computation of Sheila 's velocity right after she gets thrown out of the bike is shown below:

1) The Physical principle: conservation of momentum.

If there is no net external force operating on a system, so the system's total momentum is conserved

The momentum, p, is a vector magnitude that is determined as the product of the mass by the velocity:

P = mv.

2) Taking into account therefore that there is no net force on the device, Sheila and the momentum of the bike are the identical pre and post collision.

Based on this, the calculation is as follows

Momentum before the collision:

       $P_1 = (mass\ of\ Sheila + mass\ of\ the\ bike) \times velocity$

       $P_1 = (60kg + m) \times v_1$

= 340 kg m/s

Now Momentum after the collision:

      $P_2 = mass\ of\ sheila \times velocity\ of\ Sheila + mass\ of\ the\ bike \times velocity\ of\ the\ bike$

$P_2 = 60kg \times v_2 + m \times 0 = 60kg \times v_2$

$P_1 = P_2$

$= (60kg + m) \times v_1$

$= 60kg \times v_2$

$= 340 kg .\ m/s$

$= 60kg \times v_2$

$v_2 = \frac{340\ kg .\ m/s }{60\ kg}$

= 5.7 m/s     

Answer 2

Answer:

5.7

Explanation:

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