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
Ilia_Sergeevich [38]
3 years ago
8

A car is being lifted by a crane so that it moves upwards at a constant speed.

Physics
1 answer:
anygoal [31]3 years ago
7 0

Answer:

Explanation:

Work done is defined as the product of force and the displacement in the direction of force.

W = F x d x Cos θ

Where, θ be the angle between force and the displacement.

The force of gravity acts downwards and the displacement is in upward, so the angle is 180. cos 180 = -1 , so the work done by the force of gravity is negative.

The force of rope acting in upwards direction and displacement also in upwards direction.

So, the work done is positive

You might be interested in
Savion listed the steps involved when nuclear power plants generate electricity.
OverLord2011 [107]

Answer:

Reorder the steps so that step 4 appears before step 3

Explanation:

In a nuclear power plant, we have;

1) Nuclear reaction between the radio active species and the particles takes place to generate energy in the nucleus of atoms

2) The nuclear energy in the atom is converted into radiant energy, which is the energy found in light, and thermal (heat) energy

3) The produced radiant and thermal energy is released as heat and light

4) With the produced heat, steam is generated

5) The generated steam turns the steam turbines and produced mechanical energy

6) The produced mechanical energy is then converted into electrical energy in the electrical generator of the power plant

To correct Savion's error, Step 4) the light and heat should be released before step 3) the released heat can be used to generate steam, we therefore reorder the steps so that step 4 appears before step 3.

4 0
3 years ago
Read 2 more answers
If a net force is greater than 0 Newtons, what is the force?
goldenfox [79]

Answer:disequilibrium

Explanation:

When the net force is not zero it is called disequilibrium

5 0
3 years ago
A 1000 kg truck moving at 2.0 m/s runs into a concrete wall. It takes 0.5 s for the truck to completely stop. What is the magnit
guajiro [1.7K]

Answer:

Momentum is given by

p

=

m

v

. Impulse is the change of momentum,

I

=

Δ

p

and is also equal to force times time:

I

=

F

t

. Rearranging,

F

=

I

t

=

Δ

p

t

=

0

−

20

,

000

5

=

−

4000

N

.

Explanation:

Momentum before the collision is

p

=

m

v

=

2000

⋅

10

=

20

,

000

k

g

m

s

−

1

.

Assuming the truck comes to a complete halt, the momentum after the collision is

0

k

g

m

s

−

1

.

The change in momentum,

Δ

p

, is initial minus final

→

0

−

20

,

000

=

−

20

,

000

This is called the impulse:

I

=

Δ

p

. Impulse is also equal (check the units) to force times time:

I

=

F

t

.

We can rearrange this expression to make

F

the subject:

F

=

I

t

=

Δ

p

t

=

−

20

,

000

5

=

−

4000

N

The negative sign just means the force acting is in the opposite direction to the initial momentum.

(This will be the average force acting during the collision: collisions are chaotic so the force is unlikely to be constant.)

3 0
3 years ago
PLS HELP ME I WILL GIVE YOU BRAINLIEST
ElenaW [278]
3. Millions of years ago, the Earth was not divided into 7 continents. It was only a very large land mass, the scientists named that one land mass “Pangaea”
4. If the tectonic plates are disturbed, they can cause mass earthquakes and tsunamis.
5. The ring of fire is a massive collection of volcanoes under the pacific ocean. They all form the shape of a ring, hence the name.
SORRY, I COULDNT ANSWER THE FIRST TWO QUESTIONS.
8 0
3 years ago
Read 2 more answers
Electrons are important to electric current because they are able to
Agata [3.3K]
Electrons are important to the electric current because they are able to move from one atom to another. When an atom loses an electron, it becomes positively charged and when an atom gains an electron, it becomes negatively charged.
4 0
3 years ago
Other questions:
  • Which would show an example of how physical changes are reversible?
    7·2 answers
  • If a student connects two resistors to a circuit parallel would the total resistance increase, decrease or does it not change an
    8·1 answer
  • Definition: A command economy is where a central government makes all economic decisions. The government or a collective owns th
    15·1 answer
  • The positive muon (?+), an unstable particle, lives on average 2.20×10?6s (measured in its own frame of reference) before decayi
    15·1 answer
  • The speed of sound in ice, water, and steam is shown. What best explains the speed of sound in different states of matter?
    15·2 answers
  • How do I eat an apple?<br> I'm having trouble eating an apple.
    8·2 answers
  • If the star Alpha Centauri were moved to a distance 10 times farther than it is now, its parallax angle would
    5·1 answer
  • Mixing chemicals in a cold pack creates a reaction that:
    15·2 answers
  • Friction is a (1)______
    13·1 answer
  • The plasma membrane of a neuron has voltage-gated sodium and potassium channels. What is the effect of membrane depolarization o
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!