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3 years ago

15

A runner starts at point A runs around a 1 mile track and finishes the run back at point A. Which of the following statement is

true

1 answer:

Zanzabum3 years ago

4 0

The runner's displacement and average velocity are both zero. (I hope this answer is on the list of choices that you neglected to share.)

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A car has a momentum of 20,000 kg • m/s. what would the car’s momentum be if its velocity doubles? 10,000 kg • m/s 20,000 kg • m

babunello [35]

It would definitely be 40,000 <span>kg • m/s because if you double either the mass or velocity and the other stays the same, the momentum will double no matter what.</span>

8 0

3 years ago

Read 2 more answers

An object is at rest in front of a compressed spring. It travels over a surface that exerts a kinetic frictional force on it and

PolarNik [594]

Answer:

the object will travel 0.66 meters before to stop.

Explanation:

Using the energy conservation theorem:

$E_i+K_i+W_f=K_f+U_f$

The work done by the friction force is given by:

$W_f=F_f*d\\W_f=\µ*m*g*d\\W_f=0.35*4*9.81*d\\W_f=13.7d[J]$

so:

$\frac{1}{2}1800*(10*10^{-2})+0-13.7d=0+0\\d=0.66m$

3 0

3 years ago

A crane lifts a load of 15000N to a height 40m in 50 seconds. Calculate the power of the crane

Nataly [62]

Answer:

P = 12000 W

Explanation:

General data:

F = 15000 N
d = 40 m
t = 50 s
P = ?

Work is force times unit of distance. So in order to calculate the power we must first calculate the work.

Formula:

$\boxed{\bold{W=\frac{F}{d}}}$

Replace and solve

$\boxed{\bold{W=\frac{15000\ N}{40\ m}}}$

$\boxed{\bold{W=600000\ J}}$

once the work is found, we proceed to find the power according to the formula:

$\boxed{\bold{P=\frac{W}{t}}}$

$\boxed{\bold{P=\frac{600000\ J}{50\ s}}}$

$\boxed{\boxed{\bold{P=12000\ W}}}$

The power of the crane is <u>12000 Watts.</u>

Greetings.

6 0

2 years ago

We would like to place an object 45.0cm in front of a lens and have its image appear on a screen 90.0cm behind the lens. What mu

liubo4ka [24]

Answer:

the radii of curvature is 30 cm.

Explanation:

given,

object is place at = 45 cm

image appears at = 90 cm

focal length = ?

refractive index = 1.5

radii of curvature = ?

$\dfrac{1}{f} = \dfrac{1}{u} +\dfrac{1}{v}$

$\dfrac{1}{f} = \dfrac{1}{45} +\dfrac{1}{90}$

f = 30 cm

using lens formula

$\dfrac{1}{f} = (n-1)(\dfrac{1}{R_1} -\dfrac{1}{R_2})$

$R_1 = R\ and\ R_2 = -R$

$\dfrac{1}{f} = (n-1)(\dfrac{1}{R} +\dfrac{1}{R})$

$R = (n -1)\ f$

$R = 2(1.5 -1)\ 30$

R = 30 cm

hence, the radii of curvature is 30 cm.

3 0

3 years ago

Which of the following takes place in the combustion chamber of a gas turbine engine?A. A glow plug is used to add enough heat t

erica [24]

Answer:

Fuel oil is mixed with a proper portion of compressed air

Explanation:

A gas turbine has three main part, which are

combustion chamber
air compressor
power turbine

The combustion chamber is responsible for mixing fuel with a proper portion of compressed air.

The air compressor supplies air in sufficient quantity to satisfy the requirements of the combustion chamber

The power turbine produces the power to drive the air compressor.

6 0

3 years ago