When a boxer is moving away from a punch, the force experienced is reduced because:

A uniform rod rotates in a horizontal plane about a vertical axis through one end. The rod is 3.46 m long, weighs 12.8 N, and ro

Mkey [24]

Answer:

a. Rotational inertia: 5.21kgm²

b. Magnitude of it's angular momentum: 123.32kgm²/s

Explanation:

Length of the rod = 3.46m

Weight of the rod = 12.8 N

Angular velocity of the rod= 226 rev/min

a. Rotational Inertia (I) about its axis

The formula for rotational inertia =

I = (1/12×m×L²) + m × ( L ÷ 2)²

Where L = length of the rod

m = mass of the rod

Mass of the rod is calculated by dividing the weight of the rod with the acceleration due to gravity.

Acceleration due to gravity = 9.81m/s²

Mass of the rod = 12.8N/ 9.81m/s²

Mass of the rod = 1.305kg

Rotational Inertia =

(1/12× 1.305 × 3.46²)+ 1.305 ( 3.46÷2)²

Rotational Inertia = 1.3019115 + 3.9057345

Rotational Inertia = 5.207646kgm²

Approximately = 5.21kgm²

b. The magnitude of the rod's angular momentum about the rotational axis is calculated as

Rotational Inertia about its axis × angular speed of the rod.

Angular speed of the rod is calculated as= (Angular velocity of the rod × 2π)/60

= (226×2π) /60

= 23.67 rad/s

Rotational Inertia = 5.21kgm²

The magnitude of the rod's angular momentum about the rotational axis

= 5.21kgm²× 23.67 rad/s

= 123.3207kgm²/s

Approximately = 123.32kgm²/s

7 0

3 years ago

The table represents the forces on four objects, with directions.

noname [10]

b. Objects W and Y have balanced forces, and objects X and Z have unbalanced forces.

Explanation:

An object is said to have balanced forces if the resultant of the forces acting on it is zero. This situation occurs, for instance, when the sum of the forces on the vertical direction is zero and the sum of the forces on the horizontal direction is zero as well.

For the objects in the table, we see that:

- Object W: the resultant on the vertical direction is zero, because we have two opposite forces with same magnitude (30 N), so they cancel each other. Also, the resultant on the horizontal direction is zero, because we have two opposite forces with same magnitude (20 N), so they cancel each other.

- Object X: the resultant on the vertical direction is zero, because we have two opposite forces with same magnitude (15 N), so they cancel each other. However, the resultant on the horizontal direction is NOT zero, because we have two opposite forces but with different magnitude (35 N and 25 N), so they do not cancel each other, and they make a net force of 35 N - 25 N=10 N.

- Object Y: the resultant on the vertical direction is zero, because we have two opposite forces with same magnitude (60 N), so they cancel each other. Also, the resultant on the horizontal direction is zero, because we do not have forces along this direction.

- Object Z: the resultant on the vertical direction is zero, because we have two opposite forces with same magnitude (45 N), so they cancel each other. However, the resultant on the horizontal direction is NOT zero, because the net force is 22 N, not balanced from the other direction.

Therefore, objects W and Y have balanced forces, and objects X and Z have unbalanced forces.

5 0

3 years ago

Read 2 more answers

A 20 N force causes an impulse of 500 N*s. How long was the force applied for?

yKpoI14uk [10]

Answer:

25sec

Explanation:

Impulse = Force * time (period)

therefore,

500N*s= 20N * x(secs)

divide both sides by 20

results in 500/20=x

x= 25 secs

3 0

3 years ago

The transfer of charge from clouds to the earth or cloud to cloud is called

solong [7]

That's called "lightning".

5 0

2 years ago

Read 2 more answers

Please helppppppppppppp

artcher [175]

The ball's initial velocity must be 28.0 m/s

Explanation:

The motion of the ball in this problem is a projectile motion, so it follows a parabolic path, consisting of two separate motions:

- A uniform motion (constant velocity) along the horizontal direction

- An accelerated motion with constant acceleration (acceleration of gravity) in the vertical direction

First, we study the vertical motion of the ball: since it is a uniformly accelerated motion, we can use the suvat equation to find the time it takes for the ball to reach the ground,

$s=ut+\frac{1}{2}at^2$