Agnes who loves adventure tries to jump towards Gru who is sitting motionless on a raft with negligible mass. He tries to catch the 30 kg Agnes who is running 1.2 m/s towards him. As he caught Agnes, the motionless raft started to move. How heavy is Gru if the raft started to move with a speed of 0.5 m/s? (Note: Include correct units and sign. Ex. "20 kgm/s" , "20 Ns" , "20 kg")

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facundo3141592 facundo3141592 · Answer 1 · 2022-06-10T17:44:21+02:00

By conservation of momentum, we will see that the mass of Gru is 32 kilograms.

Here we need to use the conservation of momentum.

Initially, Gru is stop, and Agnes with a mass of 30kg has a velocity of 1.2 m/s, so the total initial momentum is:

P = 30kg*1.2m/s = 36 kg*m/s.

At the end, the total mass is M, the mass of Gru, plus the mass of Agnes:

(M + 30kg).

And the final speed is 0.5 m/s, then the final momentum is:

P' = (M + 30kg)*0.5m/s

And the final momentum must be equal to the initial momentum:

36 kg*m/s = (M + 30kg)*0.5m/s

Now we can solve that for M:

( 36 kg*m/s)/(0.5 m/s) = M + 30kg

72kg = M + 30kg

72kg - 30kg = 32 kg = M

The mass of Gru is 32 kilograms.

If you want to learn more about momentum:

https://brainly.com/question/7538238

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