E. weight = mass x gravitational field strength

A 68.0-kg person jumps from rest off a 2.20-m-high tower straight down into the water. Neglect air resistance during the descent

Margarita [4]

Answer:

$F= 1333.767\,N$

Explanation:

The velocity of the swimmer just before touching the water is:

$v = -\sqrt{2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (2.20\,m)}$

$v \approx 6.569\,\frac{m}{s}$

The average force exerted on the diver by the water is determined by the use of the Principle of Energy Conservation and the Work-Energy Theorem:

$(68\,kg)\cdot (9.807\,\frac{m}{s^{2}})\cdot (2.20\,m) +\frac{1}{2}\cdot (68\,kg)\cdot (6.569\,\frac{m}{s} )^{2}-F\cdot(2.20\,m) = 0\,J$

$F= 1333.767\,N$

6 0

3 years ago

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Two pulleys are fastened together to form an integral unit. At a certain instant, the indicated belt tensions act on the unit an

tresset_1 [31]

Answer:

α = $21.6 rad/s^2$

Explanation:

Applying the equations of motion to determine angular acceleration of the unit,

The sum of moments about O is equal to the product of angular acceleration and moment of inertia

∑Mo = Io*α

Taking the anticlockwise direction as positive moment,

= ( -(1150) + (1400) ) * (0.5 / 2) + ( (475) - (650) ) * (0.3 / 2) - F = Io*α

= 36.5 - (2.5 N.m) = $(m*ko^2)$ *α

NOTE: moment of inertia of the pulleys in this instance = $(m*ko^2)$

Hence, 33.75 = $25 * (0.25)^2$ * α

Solving, α = $21.6 rad/s^2$

8 0

3 years ago

A block of mass m, initially held at rest on a frictionless ramp a vertical distance H above the floor, slides down the ramp and

-Dominant- [34]

Answer:

Explanation:

Check attachment for solution

4 0

3 years ago

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A ball is thrown vertically upward and then comes back down. During the ball's flight up and down, its velocity and acceleration

Dovator [93]

During the ball's flight up its velocity and acceleration vectors are in opposite direction and during the ball's flight down its velocity and acceleration vectors are in same direction.

The velocity vector is always in the direction of motion of the object. So, during the ball's flight up its velocity vector is in the upward direction (90°) and during the ball's flight down its velocity vector is in the downward direction (270°).
When there is a positive acceleration in the object the acceleration vector is in the direction of motion of the object. When there is a negative acceleration in the object the acceleration vector is in the opposite direction of motion of the object. So, during the ball's flight up its acceleration vector is in the downward direction (270°) and during the ball's flight down its acceleration vector is in the upward direction (90°).

Velocity vector is the rate of change of position of an object. Acceleration vector is the rate of change of velocity of an object.

Therefore, during the ball's flight up its velocity and acceleration vectors are in opposite direction and during the ball's flight down its velocity and acceleration vectors are in same direction.

To know more about velocity and acceleration vectors

brainly.com/question/13492374

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6 0

2 years ago

A rifle bullet leaves the barrel at 1500 meters per second. If it does not slow down or hit anything, how far can it travel in h

galben [10]

Since we are dividing a second in 2, we can simply divide the amount of meters by 2.

1500/2=750

It travels 750 meters in half a second.

Hope this helps!

7 0

4 years ago