# Questions Asked onJuly 12, 2020

1. ## Physics

A block and tackle system consisting of 5 pulleys is used to raise a load of 400 N through a height of 10 m. If the work done against friction is 100 j, calculate

2. ## physics

A point charge of –3.00 μC is located at the origin; a point charge of 4.00 μC is located on the x axis at x = 0.200 m; a third point charge Q is located on the x axis at x = 0.320 m. The electric force on the 4.00 μC charge is 240 N in the +x

3. ## science

In a simple machine the energy input is 120J. If the efficiency of the machine is 80%, calculate the energy output of the machine.

4. ## Calculus

Find the maximum and minimum values of the function f(x,y)=4x^2 +9y^2 subject to xy = 4. Use Lagrange multipliers.

5. ## Physics

I need help on this question: Light bulbs are often assumed to obey Ohm's law. However, this is not really true because their resistance increases substantially as the filament heats up in its "working" state. A typical flashlight bulb at full brilliance

6. ## mathematics

am a number between 20 & 30. You can divide me into 6 equal groups. What number am I?

7. ## Physics

A 1.0 μF capacitor is being charged by a 6.0 V battery through a 10 MΩ resistor. I need help solving these parts: A) Determine the potential across the capacitor at time t=1.0s. Express your answer in volts. B) Determine the potential across the

8. ## Physics

A 6.30 μF capacitor that is initially uncharged is connected in series with a 4300 Ω resistor and a 501 V emf source with negligible internal resistance. I need help on these two questions: 1) A long time after the circuit is completed (after many time

9. ## Physics

A 3-kg toy car with a speed of 6 m/s collides head-on with a 2-kg car traveling in the opposite direction with a speed of 4 m/s. If the cars are locked together after the collision with a speed of 2 m/s, how much kinetic energy is lost? (in units of

10. ## English

According to Standard 62-1989: Ventilation for Acceptable Indoor Quality of the American Society for Heating, Refrigeration, Air Conditioning Engineers, adequate supply of outdoor air should be about 20 cubic feet per minute per occupant.

12. ## Mathmatics

Find the perimeter of a paralle logram whose base is 6cm and side 5cm

13. ## English

1. The goal of the charity was to help its target demographic integrate into U.S. society. 2. The goal of the charity was to help its target demographic integrate into the U.S. society. ====================================================== Do we have to

14. ## English

English is a language of opportunities .why should bother to learn indigenous

15. ## Physics

If the first (horizontal) resistor had zero resistance, what would be the initial voltage across the capacitor? Express your answer in terms of E. At least I know why the answer I typed into the problem, which was V_C,0 = E, was definitely incorrect,

16. ## Math

From 45ft to 92ft percentage change

17. ## psychology

Developmental psychologists study all of the following EXCEPT: -What part of the brain is involved in the development of depression - Smoking trends of adolescents - Prenatal development - Aging issues of the elderly - How personality develops across the