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2 years ago

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a worker uses a board that is 7 m long to pry up a bolder A small rock is used for the fulcrum and is placed 2.5 m from the resi

stance end of the lever, calculate the ma of the board.

1 answer:

e-lub [12.9K]2 years ago

4 0

Answer:

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As ice melts, more sunlight is absorbed. As more sunlight is absorbed, the atmosphere heats up. As the atmosphere heats up, more

Ne4ueva [31]

Answer: Conduction

Explanation: As ice melts,more sunlight is absorbed,as more sunlight is absorbed,the atmosphere heats up,as the atmosphere heats up,more ice melts. This whole process is known as CONDUCTION.

Conduction occurs when there is different temperature between two materials, when there exist a transfer energy(i.e transfer from higher-energy atoms in the hot region to the lower-energy atoms in the cold region). When the atmosphere is heated up due to sunlight,there is a rise in temperature which makes the ice to melt due to transfer of warmth it absorbed from sunlight.

3 0

3 years ago

A 5-kg projectile is fired over level ground with a velocity of 200 m/s at an angle of 25°above the horizontal. Just before it h

Nutka1998 [239]

Answer:

the change in thermal energy of the projectile is 43.8 kJ

Explanation:

Given;

mass of the object, m = 5kg

initial velocity of the projectile, v₁ = 200 m/s

final velocity of the projectile, v₂ = 150 m/s

To determine the the change in the thermal energy of the projectile and air, we consider change in potential and kinetic enrgy of the projectile. Since the projectile was fired over level ground, change in potential energy is zero.

Then, change in thermal energy of the projectile, KE = Δ¹/₂mv²

KE = Δ¹/₂mv² = ¹/₂m(v₁²-v₂²)

KE = ¹/₂ × 5(200²-150²) = 2.5(17500) = 43750 J = 43.8 kJ

Therefore, the change in thermal energy of the projectile is 43.8 kJ

8 0

3 years ago

Read 2 more answers

The block in the diagram below is AT REST. However, the tension in the cable is not the only thing holding the block back. Stati

Vedmedyk [2.9K]

Answer:

The tension in the rope is 229.37 N.

Explanation:

Given:

Mass of the block is, $m=33.2\ kg$

Coefficient of static friction is, $\mu = 0.214$

Angle of inclination is, $\theta = 31.5$ °

Draw a free body diagram of the block.

From the free body diagram, consider the forces in the vertical direction perpendicular to inclined plane.

Forces acting are $mg\cos \theta$ and normal $N$ . Now, there is no motion in the direction perpendicular to the inclined plane. So,

$N=mg\cos \theta\\N=(33.2)(9.8)\cos (31.5)\\N=277.415\ N$

Consider the direction along the inclined plane.

The forces acting along the plane are $mg\sin \theta$ and frictional force, $f$ , down the plane and tension, $T$ , up the plane.

Now, as the block is at rest, so net force along the plane is also zero.

$T=mg\sin \theta+f\\T=mg\sin \theta +\mu N\\T= (33.2)(9.8)(\sin (31.5)+(0.214\times 277.415)\\T= 170+59.37\\T=229.37\ N$

Therefore, the tension in the rope is 229.37 N.

3 0

2 years ago

Find the 24th term of the arithmetic sequence 11, 14, 17, … . Express the 24 terms of the series of this sequence using sigma no

Anna71 [15]

Answer:

The 24th term is 80 and the sum of 24 terms is 1092.

Explanation:

Given that,

The arithmetic series is

11,14,17,........24

First term a = 11

Difference d = 14-11=3

We need to calculate the 24th term of the arithmetic sequence

Using formula of number of terms

$t_{n}=a+(n-1)d$

Put the value into the formula

$t_{24}=11+(24-1)\times3$

$t_{24}=80$

$t_{24}=u_{24}=80$

We need to calculate the sum of the first 24 terms of the series

Using formula of sum,

$S_{n}=\dfrac{n}{2}(a+u_{24})$

Put the value into the formula

$S_{n}=\dfrac{24}{2}\times(11+80)$

$S_{n}=1092$

Hence, The 24th term is 80 and the sum of 24 terms is 1092.

5 0

3 years ago

You are observing traffic in a single lane of a highway at a specific location. You measure the average headway and average spac

HACTEHA [7]

Answers:

1) flow of traffic = $1198.8 veh/h$

2) average speed = $34.09 mi/h$

3)density of traffic = $34.34 veh/mi$

Explanation:

1) to find flow of traffic

we use the relation

$q=1/h$

where q is the traffic flow and h is average time headway.

$h= 3s$ $(given)$

insert the value

$q=1/3=0.333veh/s=1198.8veh/h$

2) to find average traffic speed

use the relation

$u=S/h$

where u is average speed S is average spacing and h average time

$S= 150 ft$ $(given)$

so inserting the values

$u= 150/3*3600/5280=34.09 mi/h$

3) density of traffic

$K=q/u$

where K is density of traffic q is flow of traffic and u is average speed

inserting values from above solved parts

$K=1198.8/34.09=34.34 veh/mi$

6 0

2 years ago