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
Alik [6]
3 years ago
11

If you push a heavy box at rest, you must exert some force before it begins to move. Once its moving, you don’t have to as much

force. Which of Newton’s three laws explains this?
Physics
1 answer:
dexar [7]3 years ago
3 0

Answer:

momentum does

Explanation:

You might be interested in
Your friend turns the volume up on their speaker system, so that the sound intensity is 4 times greater than it was beforehand.
erica [24]

Answer:

4

Explanation:

We know that intensity I = P/A where P = power and A = area through which the power passes through.

Now, let the initial intensity of the speaker be I₀ and its initial power be P₀. Since the intensity is increased by a factor of 4, the new intensity be I and new power be P.

So, I = P/A and I₀ = P₀/A

Now, if I = 4I₀,

P/A = 4P₀/A

P = 4P₀

Now, energy E = Pt, where t = time. So, P = E/t and P₀ = E₀/t

Substituting P and P₀ into the equation, we have

P = 4P₀

E/t = 4E₀/t

E = 4E₀

Since the energy is four times the initial energy, the energy output increases by a factor of 4.

4 0
3 years ago
• Usain Bolt can run at 10 m/s. If he runs for about 20 seconds, how far around the race track did he go?
yanalaym [24]

Answer:

200metters

Explanation:

because in one second hes going 10 metter in 20 second he will go 20×10=200

4 0
3 years ago
The electric current leaves the battery through the --- complete this blank
aev [14]
The bulb

Hope this helps!
5 0
4 years ago
An electron moving in a direction perpendicular to a uniform magnetic field at a speed of 1.6 107 m/s undergoes an acceleration
umka2103 [35]

Answer:

B = 0.024T positive z-direction

Explanation:

In this case you consider that the direction of the motion of the electron, and the direction of the magnetic field are perpendicular.

The magnitude of the magnetic force exerted on the electron is given by the following formula:

F=qvB     (1)

q: charge of the electron = 1.6*10^-19 C

v: speed of the electron = 1.6*10^7 m/s

B: magnitude of the magnetic field = ?

By the Newton second law you also have that the magnetic force is equal to:

F=qvB=ma       (2)

m: mass of the electron = 9.1*10^-31 kg

a: acceleration of the electron = 7.0*10^16 m/s^2

You solve for B from the equation (2):

B=\frac{ma}{qv}\\\\B=\frac{(9.1*10^{-31}kg)(7.0*10^{16}m/s^2)}{(1.6*10^{-19}C)(1.6*10^7m/s)}\\\\B=0.024T

The direction of the magnetic field is found by using the right hand rule.

The electron moves upward (+^j). To obtain a magnetic forces points to the positive x-direction (+^i), the direction of the magnetic field has to be to the positive z-direction (^k). In fact, you have:

-^j X ^i = ^k

Where the minus sign of the ^j is because of the negative charge of the electron.

Then, the magnitude of the magnetic field is 0.024T and its direction is in the positive z-direction

8 0
3 years ago
Pls send the answer..pls...​
Sophie [7]

Answer:

The fall in temperature of the liquid is 8.6 +/- 0.1 ⁰C

Explanation:

Given;

initial temperature of the liquid, t₁ = 76.3  +/-  0.4⁰C

final temperature of the liquid, t₂ = 67.7  +/-  0.3⁰C

The change in temperature of the liquid is calculated as;

Δt = t₂  -  t₁

Δt = (67.7 - 76.3)  +/-  (0.3 - 0.4)

Δt = (-8.6)  +/-  (-0.1)

Δt = 8.6 +/- 0.1 ⁰C

Therefore, the fall in temperature of the liquid is 8.6 +/- 0.1 ⁰C

4 0
3 years ago
Other questions:
  • A student throws a 140 g snowball at 6.5 m/s at the side of the schoolhouse, where it hits and sticks. What is the magnitude of
    9·1 answer
  • Ben walks 500 meters from his house to the corner store. He then walks back toward his house but stops to talk to a neighbor whe
    15·2 answers
  • A point charge q1 = -5.7 μC is located at the center of a thick conducting spherical shell of inner radius a = 7.4 cm and outer
    11·1 answer
  • HELP ;
    11·2 answers
  • An astronaut on the moon throws a baseball upward. the astronaut is 6ft, 6 in. tall and the initial velocity of the ball is 30 f
    14·2 answers
  • In a physics lab, light with a wavelength of 570 travels in air from a laser to a photocell in a time of 16.5 . When a slab of g
    11·1 answer
  • A train rolls to a stop along a horizontal track without the conductor applying the brakes. What answer choice BEST explains why
    9·1 answer
  • ANSWER THIS FOR BRAINY CROWN B) ITS SO EASY!
    5·2 answers
  • Please answer the question in the picture
    12·1 answer
  • According to the universal law of gravitation, the force due to gravity is b. directly proportional to the square of the distanc
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!