The expression for the block's centripetal acceleration is derived as ω²r or v²/r.
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What is centripetal acceleration?</h3>
The centripetal acceleration of an object is the inward or radial acceleration of an object moving in a circular path.
The expression for the block's centripetal acceleration is derived as follows;
ω = dθ/dt
where;
- ω is the angular speed
- θ is the angular displacement
- t is the time of motion
ac = ω²r
where;
- r is the radius of the circular path
Also, ω = v/r
ac = (v/r)²r
ac = v²/r
Thus, the expression for the block's centripetal acceleration is derived as ω²r or v²/r.
Learn more about centripetal acceleration here: brainly.com/question/79801
The hang time of the student is 0.64 seconds, and he must leave the ground with a speed of 3.13 m/s
Why?
To solve the problem, we must consider the vertical height reached by the student as max height.
We can use the following equations to solve the problem:
<u>Initial speed calculations:</u>

At max height, the speed tends to zero.
So, calculating, we have:
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<u>Hang time calculations:</u>
We must remember that the total hang time is equal to the time going up plus the time going down, and both of them are equal,so, calculating the time going down, we have have:

Then, for the total hang time, we have:

Have a nice day!
Answer:

Explanation:
Assume that the distance travelled initially is d.
In order to stop the block you need some external force which is friction.
If we use the law of energy conservation:

a)
Looking at the formula you can see that the mass doesn't affect the distance travelled, as lng as the initial velocity is constant (Which indicates that the force must be higher to push the block to the same speed) therefore the distance is the same.
b) If the velocity is doubled, then the distance travelled is multiplied by 4, because the distance deppends on the square of the velocity.
Explanation:
Calculating acceleration is complicated if both speed and direction are changing or if you want to know acceleration at any given instant in time. However, it’s relatively easy to calculate average acceleration over a period of time when only speed is changing. Then acceleration is the change in velocity (represented by Δv) divided by the change in time (represented by Δt):
acceleration=ΔvΔt
i believe thaT IT IS B BUT PLEASE TELL ME IF IM WRONG I WAS JUST USING LOGIC