Ask question

Ask question

All categories

3 years ago

14

A steel cable lying flat on the floor drags a 20 kg block across a horizontal, frictionless floor. A 110 N force applied to the

cable causes the block to reach a speed of 4.2 m/s in a distance of 2.0 m
What is the mass of the cable?
Express your answer to two significant figures and include the appropriate units.

1 answer:

sammy [17]3 years ago

5 0

Answer:

The mass of the cable is 4.94 kg

Explanation:

It is given that,

Mass of the block, m = 20 kg

Force applied to the cable, F = 110 N

Speed of the block, v = 4.2 m/s

Distance, d = 2 m

Let a is the acceleration of the block. It can be calculated using the third equation of motion as :

$v^2-u^2=2ad$

$(4.2)^2-(0)^2=2a\times 2$

$a=4.41\ m/s^2$

Let m' is the mass of the cable. It can be calculated using the second law of motion as :

$m'=\dfrac{F}{a}-m$

$m=\dfrac{110\ N}{4.41\ m/s^2}-20$

m = 4.94 kg

So, the mass of the cable is 4.94 kg. Hence, this is the required solution.

You might be interested in

If the Sun were to mysteriously turn into a black hole (don't worry . . . it won't!) and retain its current mass, what would hap

kap26 [50]

The Earth would continue to orbit it
as usual.(But it would be very cold and dark around here.)

8 0

3 years ago

Two conducting wires of the same material are to have the same resistance. One wire is 17.0 m long and 0.44 mm in diameter. If t

Anni [7]

Answer:

L = 7.90 m

Explanation:

The general expression for the resistance of a resistor is as follows:

$R = \frac{\rho*L}{A}$

When we are talking about a wire, of a given diameter, the above formula becomes as follows:

$R = \frac{\rho*L}{\frac{\pi*d^{2}}{4}}$

where ρ = resistivity of the material, L= length of the wire and d= diameter of the wire.
If both wires are from the same material, and have the same resistance, we can say the following, simplifying common terms:

$R_{1} = R_{2} = \frac{L_{1} }{d_{1}^{2} } =\frac{L_{2} }{d_{2}^{2} }$

where L₁ = 17.0 m, d₁= 0.44 mm = 4.4*10⁻⁴ m, d₂= 3*10⁻⁴ m.
Replacing these values, we can solve for L₂, as follows:

$L_{2} = \frac{L_{1} *d_{2} ^{2}}{d_{1}^{2}} = \frac{17m*(3e-4m)^{2} }{(4.4e-4m)^{2}} \ = 7.90 m$

The wire should have 7.90 m length.

5 0

3 years ago

an underground cannon launches a cannonball from ground level at a 35-degree angle. the cannonball is shot with an initial veloc

Allushta [10]

Answer:

$\displaystyle x_{max}=21.57\ m$

$\displaystyle y_{max}=3.78\ m$

Explanation:

<u>Motion in Two-Dimensions </u>

When an object is launched with a certain angle $\theta$ above ground level with an initial velocity $\vec v_o$ , it describes a curve called a parabola, defined by the force of gravity which will eventually make the object return to the ground. There are two overlapping motions, the horizontal motion, at a constant speed, and the vertical motion, at changing speed because the acceleration of gravity modifies it. The velocity $\vec v_o$ is split into two components x,y

$\displaystyle v_{ox}=|vo|\ Cos\theta$

$\displaystyle v_{oy}=|vo|\ Sin\theta$

The position of the object is also split into its components, assuming the object was launched from ground level

$\displaystyle x=v_{ox}.t$

$\displaystyle y=v_{oy}.t-\frac{g.t^2}{2}$

The maximum horizontal distance the object reaches (called range) is

$\displaystyle x_{max}=\frac{2v_{ox}\ v_{oy}}{g}$

The maximum height is given by

$\displaystyle y_{max}=\frac{v_{oy}^2}{2g}$

The question doesn't ask for anything in particular, but to guide you in the solution of your own problem, we'll compute $X_{max}$ and $Y_{max}$ for you. The data is

$\displaystyle |vo|=15\ m/s\ ,\ \theta =35^o$

Let's compute the range

$\displaystyle x_{max}=\frac{(2)(15)\ cos35^o\ (15)\ sen35^o}{9.8}$

$\displaystyle x_{max}=\frac{211.43}{9.8}=21.57\ m$

Now for the maximum height

$\displaystyle y_{max}=\frac{(15\ . \ Sin35^o)^2}{2(9.8)}$

$\displaystyle y_{max}=\frac{74.0227}{19.6}$

$\displaystyle y_{max}=3.78\ m$

6 0

3 years ago

What are two main aspects of convection that cause plate motion?

emmainna [20.7K]

Answer:

Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth's crust.

3 0

3 years ago

What two things are mixed together to create a blizzard

Whitepunk [10]

Answer: cold air moisture and warm raising hair

Explanation:

Cold air makes the snow

Moisture creates clouds that have precipitation

Warm Air causes the precipitation and clouds

8 0

3 years ago