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
rodikova [14]
3 years ago
7

A high-jumper clears the bar and has a downward velocity of - 5.00 m/s just before landing on an air mattress and bouncing up at

1.0 m/s. The mass of the high-jumper is 60.0 kg. What is the magnitude and direction of the impulse that the air mattress exerts on her
Physics
1 answer:
Jobisdone [24]3 years ago
8 0

-- As she lands on the air mattress, her momentum is (m v)

Momentum = (60 kg) (5 m/s down) = 300 kg-m/s down

-- As she leaves it after the bounce,

Momentum = (60 kg) (1 m/s up) = 60 kg-m/s up

-- The impulse (change in momentum) is

Change = (60 kg-m/s up) - (300 kg-m/s down)

Magnitude of the change = <em>360 km-m/s </em>

The direction of the change is <em>up /\ </em>.

You might be interested in
Why is it important to know the direction of the force applied to a moving object and the direction in which the object is movin
erastova [34]

Answer

(C).

When there is an angle between the two directions, the cosine of the angle must be considered.


Step by step Solution

The work done by a force is defined as the product of the force and the distance traveled in the direction of motion.

The first answer "Only the component of the force perpendicular to the motion is used to calculate the work" is wrong because, the force perpendicular to motion does no work.

The second choice "If the force acts in the same direction as the motion, then no work is done" is wrong because the work in the direction of the force is W=F\times d.

Fourth answer "A force at a right angle to the motion requires the use of the sine of the angle" is wrong because the sin(90)=0 meaning that there is no work done in the direction perpendicular to the motion.

The third answer" When there is an angle between the two directions, the cosine of the angle must be considered." is correct because the work is calculated using the force in the direction of the motion. The magnitude of this force is F\times d\times \cos(\theta).




4 0
3 years ago
Read 2 more answers
A brick and a feather fall to the earth at their respective terminal velocities. Which objectexperiences the greater force of ai
Karo-lina-s [1.5K]

Answer:

Under the reasonable assumption that the brick has more mass than the feather, the brick experiences a greater force of air friction.

Explanation:

<u>Objects at terminal velocity</u>, only under the influence of gravity, have maximized their speed and <u>have an acceleration of zero</u>.  Thus, neither object is accelerating.

Recall Newton's second law: \sum {\vec {F}}=m \vec {a}

Since acceleration for each object is zero, the sum of the force acting on each of those objects must also be zero.

Since the only forces acting on the objects are gravity and the force of air friction, in order to zero out, <u>the force of air friction must be equal in magnitude and opposite in direction to the force of gravity</u>.

Recall that near the surface of the earth, F_{gravity}=mg, so <u>the Force of Gravity acting on an object is directly proportional to the object's mass</u>.  <em>(A similar argument could be made even if this were not taking place on the surface of the earth, so long as the objects were the same distance from the object providing gravitational influence).</em>

If the masses of the objects are different, <u>the object with the greater mass will experience</u> a larger force of gravity, and hence <u>a larger force of air friction</u> at terminal velocity.  

Under the reasonable assumption that the brick has more mass than the feather, the brick experiences a greater force of air friction.

4 0
2 years ago
A spring on Earth has a 0.500 kg mass suspended from one end and the mass is displaced by 0.3 m. What will the displacement of t
julia-pushkina [17]

To solve this problem we will apply the concepts related to the Force of gravity given by Newton's second law (which defines the weight of an object) and at the same time we will apply the Hooke relation that talks about the strength of a body in a system with spring.

The extension of the spring due to the weight of the object on Earth is 0.3m, then

F_k = F_{W,E}

kx_1 = mg

The extension of the spring due to the weight of the object on Moon is a value of x_2, then

kx_2 = mg_m

Recall that gravity on the moon is a sixth of Earth's gravity.

kx_2 = m\frac{g}{6}

kx_2 = \frac{1}{6} mg

kx_2 = \frac{1}{6} kx_1

x_2 = \frac{1}{6} x_1

We have that the displacement at the earth was x_1 = 0.3m, then

x_2 = \frac{1}{6} 0.3

x_2 = 0.05m

Therefore the displacement of the mass on the spring on Moon is 0.05m

6 0
3 years ago
The Netherlands controlled ______ for centuries <br><br> A. Vietnam<br> B. Malaysia<br> C. Indonesia
gogolik [260]
The Netherlands controlled Indonesia for centuries!
4 0
3 years ago
Read 2 more answers
The diagram shows a screwdriver being used as a lever to open a tin
Musya8 [376]

Answer:

(a) Most reactive {}       Metal B

{}                                    Metal D

{}                                    Metal A

Least reactive {}           Metal C

(b) (i) Bubbles should form very slowly

(ii) No reaction takes place

Explanation:

(a) The given metals arranged in their order of reactivity are;

Most reactive {}       Metal B

{}                               Metal D

{}                               Metal A

Least reactive {}      Metal C

The other of reactivity is based on the nature of their reactivity of the metals in air

(b) (i) Based on the reactivity of the metals in air, whereby metal A reacts very slowly and an oxide is formed, we have that, based on the reactivity of the metal A, when mixed with dilute hydrochloric acid, bubbles should form very slowly

(ii) Similarly, given that metal C is unreactive, we have that when small pieces of metal C are added to dilute hydrochloric acid, no reaction takes place.

7 0
3 years ago
Other questions:
  • 1) Describe the motions of the moon relative to the Earth and the sun. Explain how this causes us to see phases of the moon, and
    12·1 answer
  • What type of wave is produced when you move one end of a horizontal spring up and down?
    14·1 answer
  • Which of the three recording stations was closest to the epicenter of the earthquake, based on the seismograms shown below?
    5·2 answers
  • 6. On a quiet day, the atmospheric pressure results in a force of about 10,0000 N on a window pane with an area of 1 square mete
    7·1 answer
  • 1. calculate agni's average speed during the race.
    9·1 answer
  • A heat engine does 300 J of work during one cycle. In this cycle 900 J of energy is wasted.
    7·2 answers
  • A flat coil is wrapped with 200 turns of very thin wire on a square frame with sides 18 cm long. A uniform magnetic field is app
    5·1 answer
  • Joan makes the device shown in her science class. What would happen to the magnetic field if she connects the battery in the opp
    15·2 answers
  • Who think's im pretty <br> the pic is a lil hard to see
    13·1 answer
  • Ano ang pagkain a ng Bugtong sa Palaisipan?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!