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AURORKA [14]
3 years ago
11

An average person can reach a maximum height of about 60 {\rm cm} when jumping straight upfrom a crouched position. During the j

ump itself, the person's bodyfrom the knees up typically rises a distance of around 50 {\rm cm}. To keep the calculationssimple and yet get a reasonable result, assume that the entirebody rises this much during the jump. In terms of this jumper's weight W , what force does the ground exert on him or herduring the jump?
Physics
1 answer:
Sunny_sXe [5.5K]3 years ago
3 0

Answer:

2.2 W where W is the weight of the jumper.

Explanation:

A) use the formula

V^2 = 2gh= 2*9.81*60

that gives

V = 3.43 m/s

b) W = mg

during the jump , the displacement of the body is d =0.5m

so the acceleration a = (V^2-Vo^2)/2d = 11.76 m/s^2

net force applied by ground = m(g+a) = W/g(g+a)

= 2.2 W

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2. A multipurpose wiring tool can be used to
Alex_Xolod [135]

Answer:

Option C

Crimp terminals

Explanation:

It's possible to crimp terminals using a multipurpose wiring tool. Since the tool  selected for use during crimping also depends on the volume of work, the multipurpose wiring tool is recommended for use when the volume is small to medium. Basically, crimping tools are sized according to the wire gauge that they can fit. Since multipurpose has different sizes, that's why it's used for crimping tools.

5 0
4 years ago
A. A child is twirling a 1.52 kg object in a vertical circle with a radius of 67.6
steposvetlana [31]

Answer:

(a) 4.21 m/s

(b) 24.9 N

Explanation:

(a) Draw a free body diagram of the object when it is at the bottom of the circle.  There are two forces on the object: tension force T pulling up and weight force mg pulling down.

Sum the forces in the radial (+y) direction:

∑F = ma

T − mg = m v² / r

v = √(r (T − mg) / m)

v = √(0.676 m (54.7 N − 1.52 kg × 9.8 m/s²) / 1.52 kg)

v = 4.21 m/s

(b) Draw a free body diagram of the object when it is at the top of the circle.  There are two forces on the object: tension force T pulling down and weight force mg pulling down.

Sum the forces in the radial (-y) direction:

∑F = ma

T + mg = m v² / r

T = m v² / r − mg

T = (1.52 kg) (4.21 m/s)² / (0.676 m) −  (1.52 kg) (9.8 m/s²)

T = 24.9 N

6 0
3 years ago
4) A football player starts at the 40-yard line, and runs to the 25-yard line in 2 seconds.
VMariaS [17]

Answer:

(a). Their speed during that run is 10 m/s.

(b). Their velocity is 6.86 m/s

(c). The final position is at 8.91 m.

Explanation:

Given that,

A football player starts at the 40-yard line, and runs to the 25-yard line in 2 seconds.

Suppose, the distance between 40 yard line and 25 yard line is 20 yard.

(a). We need to calculate their speed during that run

Using formula of speed

v=\dfrac{d}{t}

Where. d = distance

t = time

Put the value into the formula

v=\dfrac{18.288}{2}

v=10\ m/sduring that run

(b). We need to calculate their velocity

Using formula of speed

v=\dfrac{\Delta d}{\Delta t}

Put the value into the formula

v=\dfrac{22.86-36.58}{2}

v=-6.86\ m/s

Negative sign shows the direction of motion.

(c). If they kept running at that velocity for another 1.3 seconds,

We need to calculate the final position

Using formula of position

d=vt

Put the value into the formula

d=6.86\times1.3

d=8.91\ m

Hence, (a). Their speed during that run is 10 m/s.

(b). Their velocity is 6.86 m/s

(c). The final position is at 8.91 m.

8 0
3 years ago
Polly is pushing a box across the floor with a force of 30 N. The force of gravity is -8 in, and the normal force is eight in. W
aleksandr82 [10.1K]

Answer:

A. -30 N

Explanation:

not sure but if the box isn't moving then the force opposite of Polly would be equal to the force she's exerting.

5 0
2 years ago
Read 2 more answers
Estimate the moment of inertia of a bicycle wheel 66 cm in diameter. The rim and tire have a combined mass of 1.2 Kg
Fed [463]
<span>For a point mass the moment of inertia is just the mass times the square of perpendicular distance to the rotation axis, I = mr^2. That point mass relationship becomes the basis for all other moments of inertia since any object can be built up from a collection of point masses. So the I = (1.2 kg)(0.66m/2)^2 = 0.1307 kg m2</span>
3 0
3 years ago
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