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Lemur [1.5K]
3 years ago
14

Dan is gliding on his skateboard at 2.00 m/s . He suddenly jumps backward off the skateboard, kicking the skateboard forward at

7.00 m/s (as measured by an observer on the ground). Dan's mass is 40.0 kg and the skateboard's mass is 7.00 kg .
Physics
1 answer:
miss Akunina [59]3 years ago
4 0

Answer:

The velocity of Dan is 1.13 m/s.

Explanation:

Given that,

Initial velocity of skateboard and Dan = 2.00 m/s

Velocity of skateboard = 7.00 m/s

Mass of Dan m= 40.0 kg

Mass of skateboard M= 7.00 Kg

Suppose How fast is Dan going as his feet hit the ground?

We need to calculate the initial velocity of Dan

Using conservation of momentum

(m+M)v_{i}=mv_{f}+Mv_{f}

Put the value into the formula

(40.0+7.00)\times2.00=40.0\times v_{i}+7.00\times7.00

v_{i}=\dfrac{(40.0+7.00)\times2.00-7.00\times7.00}{40.0}

v_{i}=1.13\ m/s

Hence, The velocity of Dan is 1.13 m/s.

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