Answer:
Mass of the box = 0.9433 kg
Explanation:
Mass of racket-ball = 0.00427 kg
Velocity of racket-ball before collision = 22.3 m/s
Velocity of racket-ball after collision with box = -11.5 m/s
[Since ball is bouncing back, so velocity is taken negative.]
Velocity of the box before collision = 0 m/s
<em>[Since the box is stationary, so velocity is taken zero]</em>
Velocity of box moving forward after collision = 1.53 m/s
To find the mas of the box .
By law of conservation of momentum we have:
Momentum before collision = Momentum after collision
This can be written as:
We can plugin the given value to find
Adding both sides by 0.4911
Dividing both sides by 1.53.
∴ kg
Mass of the box = 0.9433 kg (Answer)
Complete Question
An athlete at the gym holds a 3.0 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg. Assume, a bit unrealistically, that the athlete's arm is uniform.
What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? Include the torque due to the steel ball, as well as the torque due to the arm's weight.
Answer:
The torque is
Explanation:
From the question we are told that
The mass of the steel ball is
The length of arm is
The mass of the arm is
Given that the arm of the athlete is uniform them the distance from the shoulder to the center of gravity of the arm is mathematically represented as
=>
=>
Generally the magnitude of torque about the athlete shoulder is mathematically represented as
=>
=>
The statement which is true about a polarized object would be "the number of the positive and negative charges can be the same." Polarized objects became polarized and it has its center of positive charges separated from negative charges.