1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Zepler [3.9K]
3 years ago
5

Rachel has been reading her physics book. She takes her weighing scales into an elevator and stands on them. If her normal weigh

t is 690 N (155 lbs) and the elevator moves upward at 0.25 g and then down at 0.25 g, what is the difference between the up and down scale readings?
Physics
1 answer:
GrogVix [38]3 years ago
4 0

Answer:

345 N

Explanation:

Given:

Normal weight of Rachel (mg) = 690 N

Case 1: Upward motion of elevator

Given:

Acceleration of elevator (a) = 0.25 g

The scale reading is given by the normal force acting on Rachel. Let N₁ be the normal force.

So, the net force acting on Rachel is given as:

F_{net}=N_1-mg=N_1-690

Now, from Newton's second law:

F_{net}=ma\\\\N_1-690=m\times 0.25g\\\\N_1-690=0.25\times (mg)\\\\N_1-690=0.25\times 690\\\\N_1=690+172.5=862.5\ N------(1)

Case 2: Downward motion of elevator

Given:

Acceleration of elevator (a) = 0.25 g

The scale reading is given by the normal force acting on Rachel. Let N₂ be the normal force.

So, the net force acting on Rachel is given as:

F_{net}=mg-N_2=690-N_2

Now, from Newton's second law:

F_{net}=ma\\\\690-N_2=m\times 0.25g\\\\690-N_2=0.25\times (mg)\\\\690-N_2=0.25\times 690\\\\N_2=690-172.5=517.5\ N------(2)

Now, the difference in the scale reading is obtained by subtracting equation (2) from equation (1). This gives,

Difference=N_1-N_2=862.5-517.5=345\ N

Therefore, the difference between the up and down scale readings is 345 N.

You might be interested in
When you break a magnet in half how many poles does each piece have.
Anastaziya [24]
It will have two poles
7 0
3 years ago
Twenty grams of a solid at 70°C is place in 100 grams of a fluid at 20°C. Thermal equilibrium is reached at 30°C.
zaharov [31]

Answer:

c. is more than that of the fluid.

Explanation:

This problem is based on the conservation of energy and the concept of thermal equilibrium

heat= m s \Delta T


m= mass

s= specific heat

\DeltaT=change in temperature

let s1= specific heat of solid and s2= specific heat of liquid

then

Heat lost by solid= 20(s_1)(70-30)=800s_1


Heat gained by fluid=100(s_2)(30-20)=1000s_2


Now heat gained = heat lost

therefore,

1000 S_2=800 S_1

S_1=1.25 S_2

so the specific heat of solid is more than that of the fluid.

8 0
3 years ago
a hippopotamus produces a pressure of 250000 pa when it is standing on all four feet if the weight of the hippo is 40000 N what
mamaluj [8]

0.04m²

Explanation:

Given parameters:

Pressure = 250000Pa

Weight = 40000N

Unknown:

Area of each foot = ?

Solution:

Pressure is the force exerted per unit area of a body

  Pressure = \frac{force}{area}

To find the area;

        Area = \frac{force }{pressure}

    Area = \frac{40000}{250000} = 0.16m²

The force exerted by all the four feet is 0.16m²

the area of each feet = \frac{0.16}{4} = 0.04m²

Learn more:

Pressure brainly.com/question/7139767

#learnwithBrainly

8 0
3 years ago
The largest building in the world by volume is the Boeing 747 plant in Everett, Washington. It measures approximately 634 m long
Mazyrski [523]
So to get the volume, you're going to multiply all three together, but you have to make all the units the same first. The answer wants ft³, so you want to convert them all to feet. height = 109 ft, so that's fine already. Awesome. width = 710 yd, but that's an easy conversion to feet. Three feet equal one yard, so just multiply (710 yd) by (3 ft/1 yd) and that'll give you the width in ft. length = 634 m This one is a little tricker, but same principle. First convert meters to centimeters, like this: (634 m)(100 cm/1 m). Then take that number in cm and convert it into inches, knowing that 1 inch = 2.54 centimeters. So multiply the inches you have by (1 in/2.54 cm). Then you'll change that number into feet by dividing it by twelve, since there are twelve inches in each foot. Now you have all three measurements in feet. Just multiply them together to get the volume in ft³ and you're good to go! :)
8 0
3 years ago
Read 2 more answers
6. A 4 kg object hangs below a 6 kg object by a string of negligible mass. If the 6 kg object is pulled upward by a force of 440
MrRissso [65]

Answer:

T =176 N

Explanation:

from diagram

F -(m_1+m_2_g) = (m_1+m_2_g)a

440 - (6+4)g = (6+4)a

a =\frac{440-10*9.8}{10}

a =34.2 m/s^2

frrom free body diagram of mass m2 = 4kg

T -m_2g =m_2a

T = m_2(g +a)

T = 4(9.81+34.2)

T =176 N

7 0
3 years ago
Other questions:
  • A. Which of the four thermal processes describes the pressure-volume relationship at a constant temperature?
    8·2 answers
  • force of 10 lb is required to hold a spring stretched 4 in. beyond its natural length. How much work W is done in stretching it
    5·1 answer
  • 38 Points + Brainlyest!!!
    8·2 answers
  • The word back is up there!!!
    10·1 answer
  • A 3-cm high object is in front of a thin lens. The object distance is 4 cm and the image distance is –8 cm. (a) What is the foca
    7·1 answer
  • What information do you need to describe an object's location
    7·1 answer
  • What is the magnitude of force required to accelerate a car of mass 1.7 * 10 ^ 3 kg by 4.75 m/s
    13·1 answer
  • PLEASE HELP! I'LL GIVE BRAINLEST​
    10·1 answer
  • You want to calculate the area of your dorm
    13·1 answer
  • Worth 25 points on my exam
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!