physics 100

posted by .

Bob, who has a mass of 60 , can throw a 800 rock with a speed of 26 . The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 .

a) What constant force must Bob exert on the rock to throw it with this speed?

b)If Bob is standing on frictionless ice, what is his recoil speed after releasing the rock?

  • physics 100 -

    You need to provide dimensions with your numbers.

  • physics 100 -

    m1=60 kg, m2=0.8 kg, v=26m/s, s=1 m
    (a). a=v²/2s =26²/2•1=338 m/s²
    F=m1•a=60•338=20280 N (inhumanly large force... I believe that velocity has to be 2.6 m/s .... check your given data)
    (b)The law of conservation of linear momentum
    0= m1•v1-m2•v2
    v1= m2•v2/m1= 0.8•26/60=0.347 m/s

  • physics 100 -

    b. F = m*a = 0.8 * 338 = 270.4 N.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 94.0 kg. The mass of the rock is 0.350 kg. Initially the wagon is …
  2. physics

    Bob can throw a 540 g rock with a speed of 26 m/s. He moves his hand forward 0.8 m while doing so. What is Bob's maximum power output as he throws the rock?
  3. physics

    Bob can throw a 540 g rock with a speed of 26 m/s. He moves his hand forward 0.8 m while doing so. What is Bob's maximum power output as he throws the rock?
  4. physics

    One day I decide I want to see how high I can throw a rock. I throw a rock straight up in the air and it has a speed of 30 m/s when it leaves my hand. I then realize this was foolish, as I need to get out of the way before the rock …
  5. Physics

    A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 94 kg. The mass of the rock is 0.27 kg. Initially the wagon is rolling …
  6. physics

    Bob, who has a mass of 75 kg, can throw a 500 g rock with a speed of 30 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. a. What constant force must Bob exert …
  7. physics

    A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.540 m/s. The total mass of the sled, man, and rock is 93.5 kg. The mass of the rock is 0.300 kg and the man can throw …
  8. physics

    A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 90 kg. The mass of the rock is 0.26 kg. Initially the wagon is rolling …
  9. physics

    You attempt to throw the rock across the chasm with a velocity of 35 m/s at and angle of 60 degrees above horizontal. Calculate and label the forward velocity (components) of the rock as it leaves your hand. How long will it take to …
  10. physics

    Bob, who has a mass of 80kg , can throw a 550g rock with a speed of 27m/s . The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. What constant force must Bob exert on …

More Similar Questions