Answer:
They are able to balance torques due to gravity.
Explanation:
When two friends of different masses will balance themselves on see saw then at equilibrium position the see saw will remain horizontal
This condition will be torque equilibrium position where the see saw will not rotate
Here we can say
here we know that force is due to weight of two friends
and their positions are different with respect to the lever about which see saw is rotating
since both friends are of different weight so they will balance themselves are different positions as per above equation
The minimum input force she'll need to lift the ball is 35 N.
Explanation:
Mechanical advantage of a single pulley is 1. As, she applies 70 N of force to lift the bowling ball, so the output force(weight of the ball) is also 70 N.
Now, adding another pulley gives a mechanical advantage of 2. We have,
M.A = (Output Force)/(Input Force)
Substituting the values we get,
= 35 N
Input force equals to 35 N needs to be applied.
D. Atoms.
Explanation:
All the matter is made of elementary particles called "atoms".
Further, an atom is made of electrons, protons and neutrons. The electrons & protons are again made of the fundamental sub-particles, electrons (leptons) and the protons(quarks).
The classification of particles is shown in the figure attached
The speed of the ball is always zero and the acceleration is always -g when it reaches the top of its motion. This is because when the ball is free, only gravity acts on it which is always downwards, hence g is the net acceleration and it is always negative. However the velocity does not direction change instantly, negative acceleration first slows down the ball with a positive velocity, until that point the ball keeps moving up, then the ball velocity becomes zero just before changing direction and becoming negative after which the ball will now go down along gravity. Hence the ball velocity is zero at the top (neither going up nor down). Mathematically this can be seen as velocity is the integration of acceleration.
Answer:
26.67 m/s
Explanation:
From the law of conservation of linear momentum, the initial sum of momentum equals the final sum.
p=mv where p is momentum, m is the mass of object and v is the speed of the object
Initial momentum
The initial momentum will be that of basketball and volleyball, Since basketball is initially at rest, its initial velocity is zero
Final momentum
