All categories

2 years ago

4. A cinder block is sitting on a platform 20 m high. It has a mass of 4 kg. The block has energy. Calculate it.

Physics

1 answer:

zavuch27 [327]2 years ago

4 0

Answer:

Explanation:

Since the block is at rest in an elevated position, we can assume that it only has potential energy.

U=mgh is the formula for potential energy where U=potential energy, m= mass, g=acceleration due to gravity, and h=height.

Plug in known variables....

U=4kg*9.8m/s^2*20m

U=784 joules of potential energy or letter A.

You might be interested in

HURRY PLS WILL RATE AND THANKS AND BRAINLIEST

Rus_ich [418]

It would be the 2nd one because the higher the farther away from the equator. <span />

3 0

2 years ago

Which of the following is the most effective relaxation technique?

nevsk [136]

Answer:

Explanation:

It varies from person to person.

3 0

2 years ago

Read 2 more answers

The length of the minute hand of the clock is 14cm. Calculate the speed with which the tip of the minute hand moves

Molodets [167]

Speed of the tip of the minute hand=V=0.0244 cm/s

Explanation:

The angular velocity of the minute hand is given by

$\omega= \frac{2\pi}{T}$

T= time period of the minute hand=60 min=3600 s

so ω= 2 π/3600 rad/s

Now linear velocity v= r ω

r= radius of minute hand=14 cm

so v= 14 (2 π/3600)

V=0.0244 cm/s

8 0

2 years ago

A car travels 60 miles due West first then turns back and travels 120 miles due East in 3 hours. What is...

ella [17]

Answer:

<h2>A. 180 miles</h2><h2>B. 60 miles</h2><h2 />

Explanation:

In this problem, we are required to solve for the total distance that the car travelled. and the displacement

A) the distance travelled by car

this can be gotten by summing all the distances the car has travelled.

i,e total distance= 60 miles+120 miles

total distance= 180 miles

B) the displacement of the car

the displacement can be gotten by subtracting the final distance from the initial distance

final distance = 120 miles

initial distance= 60 miles

displacement= 120-60= 60 miles

7 0

3 years ago

A 0.10 g honeybee acquires a charge of +23 pC while flying.

kari74 [83]

Answer:

a) $\frac{F}{w} =2.347\times 10^{-6}\ N$

b) $E=4.2609\times 10^7\ N.C^{-1}$ parallel to the earth surface.

In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.

Explanation:

Given:

mass of the bee, $m=10^{-4}\ kg$

charge acquired by the bee, $q_2=23\times 10^{-12}\ C$

Electrical field near the earth surface, $E=100\ N.C^{-1}$

Now the electric force on the bee:

we know:

$F=\frac{1}{4\pi.\epsilon_0} \times \frac{q_1.q_2}{r^2}$

$F=E.q_2$

$F=100\times 23\times 10^{-12}$

$F=23\times 10^{-10}\ N$

The weight of the bee:

$w=m.g$

$w=10^{-4}\times 9.8$

$w=9.8\times10^{-4}\ N$

Therefore the ratio :

$\frac{F}{w} =\frac{23\times 10^{-10}}{9.8\times10^{-4}}$

$\frac{F}{w} =2.347\times 10^{-6}\ N$

The condition for the bee to hang is its weight must get balanced by the electric force acing equally in the opposite direction.

So,

$F=9.8\times10^{-4}\ N$

$E.q_2=9.8\times10^{-4}\ N$

$E\times 23\times 10^{-12}=9.8\times10^{-4}\ N$

$E=4.2609\times 10^7\ N.C^{-1}$ parallel to the earth surface.

In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.

3 0

2 years ago