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2 years ago

10. Calculate the kinetic energy of a running back that has a mass of 80 kg and

Physics

1 answer:

EastWind [94]2 years ago

5 0

Answer:

The answer is

Explanation:

The kinetic energy of an object given it's mass and velocity can be found by using the formula

$KE = \frac{1}{2} m {v}^{2}$

where

m is the mass

v is the velocity

From the question

m = 80 kg

v = 8 m/s

The kinetic energy is

$KE = \frac{1}{2} \times 80 \times {8}^{2} \\ = 40 \times 64$

We have the final answer as

Hope this helps you

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Froghopper insects have a typical mass of around 11.3 mg and can jump to a height of 58.8 cm. The takeoff velocity is achieved a

allochka39001 [22]

Answer:

2874.33 m/s²

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

g = Acceleration due to gravity = 9.81 m/s²

$v^2-u^2=2as\\\Rightarrow a=\frac{v^2-u^2}{2s}\\\Rightarrow a=\frac{v^2-0^2}{2\times h}\\\Rightarrow v^2=2ah\ m/s$

Now H-h = 0.588 - 0.002 = 0.586 m

The final velocity will be the initial velocity

$v^2-u^2=2as\\\Rightarrow 0^2-u^2=2gs\\\Rightarrow -2ah=2\times g(H-h)\\\Rightarrow -2a0.002=2\times g0.586\\\Rightarrow a=-\frac{0.586\times -9.81}{0.002}\\\Rightarrow a=2874.33\ m/s^2$

Acceleration of the frog is 2874.33 m/s²

6 0

3 years ago

A certain quantity of steam has a temperature of 100.0 oC. To convert this steam into ice at 0.0 oC, energy in the form of heat

KonstantinChe [14]

Answer:

2452.79432 m/s

Explanation:

m = Mass of ice

$L_s$ = Latent heat of steam

$s_w$ = Specific heat of water

$L_i$ = Latent heat of ice

v = Velocity of ice

$\Delta T$ = Change in temperature

Amount of heat required for steam

$Q_1=mL_s\\\Rightarrow Q_1=m(2.256\times 10^6)$

Heat released from water at 100 °C

$Q_2=ms_w\Delta T\\\Rightarrow Q_2=m4186\times (100-0)\\\Rightarrow Q_2=m0.4186\times 10^6$

Heat released from water at 0 °C

$Q_3=mL_i\\\Rightarrow Q_3=m(333.5\times 10^3)\\\Rightarrow Q_3=m(0.3335\times 10^6)$

Total heat released is

$Q=Q_1+Q_2+Q_3\\\Rightarrow Q=m(2.256\times 10^6)+m0.4186\times 10^6+m(0.3335\times 10^6)\\\Rightarrow Q=3008100m$

The kinetic energy of the bullet will balance the heat

$K=Q\\\Rightarrow \frac{1}{2}mv^2=3008100m\\\Rightarrow v=\sqrt{2\times 3008100}\\\Rightarrow v=2452.79432\ m/s$

The velocity of the ice would be 2452.79432 m/s

6 0

3 years ago

A device consisting of four heavy balls connected by low-mass rods is free to rotate about an axle. It is initially not spinning

zubka84 [21]

The angular speed of the device is 1.03 rad/s.

<h3>What is the conservation of angular momentum?</h3>

A spinning system's ability to conserve angular momentum ensures that its spin will not change until it is subjected to an external torque; to put it another way, the rotation's speed will not change as long as the net torque is zero.

Using the conservation of angular momentum

$L_{i}=L_{f}$

Here, = the system's angular momentum before the collision

$L_{i}$ = 0 + mv

= (0.005)(450)(0.752)

= 1.692 kgm²/s

The moment of inertia of the system is given by

I = 2(M₁R₁² + M₂R₂²)+ mR₁²

= 2[(1.2)(0.8)² +(0.5)(0.3)²]+0.005(0.8)²

= 1.6292 kgm²

Here, = Iω

So,

1.692 = 1.6292(ω)

ω = 1.03 rad/s

To know more about the conservation of angular momentum, visit:

brainly.com/question/1597483

#SPJ1

4 0

1 year ago

Read 2 more answers

What is a net force on an object that has a mass of 20.0 kg, an applied force of 100 n moving on a surface with a friction coeff

sergiy2304 [10]

The net force on the object as described is; 58.84N

Two forces acting on the object are;

The <em>applied force and the frictional force.</em>

In essence; the frictional force can be evaluated as;

Frictional force; = coefficient × Weight of object.

Frictional force = 0.21 × 20 × 9.8.

Frictional force = 41.16N

The Net force = Applied force - frictional force

Net force = 100 - 41.16N

Net Force = 58.84 N.

brainly.com/question/94428

5 0

2 years ago

Choose all the answers that apply.

horrorfan [7]

Answer:

orbit the sun have very elliptical orbits

are made of frozen gas and ice

Explanation:

Comets are the made up of dry ice, frozen water, gases and dust particles. it is called dirty snow balls as their nucleus carry frozen water and pieces of rock.

Comets move around the sun in an elliptical orbits and follow Kepler's Laws saying that they move faster when closer to the Sun.

Comets have tails even when they are far from the sun and the tails that point away from the sun.

Hence, the correct options are "orbit the sun have very elliptical orbits and are made of frozen gas and ice".

6 0

3 years ago

Read 2 more answers