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
SpyIntel [72]
2 years ago
6

I need help with questions b and d, that’s all. Thank you.

Physics
1 answer:
Mkey [24]2 years ago
7 0

b).  The power depends on the RATE at which work is done.  

Power = (Work or Energy) / (time)

So to calculate it, you have to know how much work is done AND how much time that takes.

In part (a), you calculated the amount of work it takes to lift the car from the ground to Point-A.  But the question doesn't tell us anywhere how much time that takes.  So there's NO WAY to calculate the power needed to do it.

The more power is used, the faster the car is lifted.  The less power is used, the slower the car creeps up the first hill.  If the people in the car have a lot of time to sit and wait, the car can be dragged from the ground up to Point-A with a very very very small power ... you could do it with a hamster on a treadmill.  That would just take a long time, but it could be done if the power is small enough.

Without knowing the time, we can't calculate the power.

...

d).  Kinetic energy = (1/2) · (mass) · (speed squared)

On the way up, the car stops when it reaches point-A.  

On the way down, the car leaves point-A from "rest".

WHILE it's at point-A, it has <u><em>no speed</em></u>.  So it has no (<em>zero</em>) kinetic energy.

You might be interested in
A 6 N and a 10 N force act on an object. The moment arm of the 6 N force is 0.2 m. If the 10 N force produces five times the tor
Levart [38]

Answer:

The moment arm is 0.6 m

Explanation:

Given that,

First force F_{1}=6\ N

Second force F_{2}=10\ N

Distance r = 0.2 m

We need to calculate the moment arm

Using formula of torque

\tau=Force\times lever\ arm

So, Here,

\tau_{2}=5 \tau_{1}

We know that,

The torque is the product of the force and distance.

Put the value of torque in the equation

F_{2}\times d_{2}=5\times F_{1}\times r_{1}

r_{2}=\dfrac{5\times F_{1}\times r_{1}}{F_{2}}

Where, F_{1}=First force

F_{1}=First force

F_{2}=Second force

r_{1}= distance

Put the value into the formula

r_{2}=\dfrac{5\times6\times0.2}{10}

r_{2}=0.6\ m

Hence, The moment arm is 0.6 m

6 0
3 years ago
A stereo speaker produces a pure \"E\" tone, with a frequency of 329.6 Hz. What is the period of the sound wave produced by the
olya-2409 [2.1K]

Answer:

0.003034 s

1.035 m

4.5 m

Explanation:

f = frequency of the tone = 329.6 Hz

T = Time period of the sound wave

we know that, Time period and frequency are related as

T =\frac{1}{f}\\T =\frac{1}{329.6}\\T = 0.003034 s

v = speed of the sound in the air = 341 ms⁻¹

wavelength of the sound is given as

\lambda =\frac{v}{f} \\\lambda =\frac{341}{329.6}\\\lambda = 1.035 m

v = speed of the sound in the water = 1480 ms⁻¹

wavelength of the sound in water is given as

\lambda =\frac{v}{f} \\\lambda =\frac{1480}{329.6}\\\lambda = 4.5 m

8 0
3 years ago
Paula has walked in a straight line, 30.5° north of west, for 1650 meters. How far south and east should she walks to return to
olchik [2.2K]
The answer is A.
Sy = 1650 x sin30.5 = 837.4 m toward south
Sx = 1650 x cos30.5 = 1421.7 m toward east
8 0
2 years ago
What force is represented by the vector?
choli [55]
Well I think B hope this helps
8 0
2 years ago
Read 2 more answers
SUB TO YFBG JAY ON YT RN ASAP
Svet_ta [14]
Oki said he would not hood him to go on a bike but i said he would be ok if you don’t have a ride home with you and green one for a
6 0
2 years ago
Other questions:
  • a car with a mass of 1200 kilograms is moving around a circular curve at a uniform velocity of 20 meters per second. the centrip
    12·1 answer
  • How much work is done when you push a crate horizontally with 150 N across a 13-m floor
    7·1 answer
  • Utility poles are to be set every 30 meters. How many poles will be set in one mile if one was set at the beginning of the mile)
    11·2 answers
  • Rank the following in terms of increasing momentum:
    9·2 answers
  • Which of the following people believed that light behaved like a wave?
    8·1 answer
  • Facts about Tsunami?
    9·1 answer
  • A 1100 kgkg safe is 2.4 mm above a heavy-duty spring when the rope holding the safe breaks. The safe hits the spring and compres
    10·1 answer
  • Which source would provide the most reliable information about the safety of nuclear power plants?
    13·1 answer
  • When a 1.7 m tall man stands, his brain is 0.5 m above his heart.
    12·1 answer
  • How does density affect refraction
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!