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
larisa86 [58]
3 years ago
5

A 7kg block slides down a 30 degree slope at a constant velocity of 2 m/s. How big is the force of friction acting on the block?

Physics
1 answer:
lisabon 2012 [21]3 years ago
6 0

The force of friction is <u>34.3 N.</u>

A block of mass m slides down a plane inclined at an angle θ to the horizontal with a constant velocity.  According to Newton's first law of motion, every body continues in its state of rest or a state of uniform motion in a straight line, unless acted upon, by an external unbalanced force. This means that when balanced forces act on a body, the body moves with a constant velocity.

The free body diagram of the sliding block is shown in the attached diagram. Resolve the weight mg of the block into two components  mg sinθ along the direction of the plane and mg cosθ perpendicular to the plane . The force of friction   F acts upwards along the plane  and the normal reaction acts perpendicular to the plane.

Since the block moves down with a constant velocity, the downward force mg sinθ must be equal to the upward frictional force.

F = mg sin\theta

Substitute 7 kg for m, 9.8 m/s² for g and 30° for θ.

F = mg sin\theta = (7 kg)(9.8 m/s^2)(sin30^o) =34.3 N

The force of friction is <u>34.3 N</u> up the plane.


You might be interested in
Which is the BEST definition of refraction? A) Light or sound waves change direction. B) Light or sound waves bounce off a mediu
melisa1 [442]
The answer to this is A. this is because, refraction with a light or sound wave changing its direction involve propagation,(in which propagation is the change in direction of a light or sound wave)


4 0
3 years ago
Read 2 more answers
1. A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed?
bulgar [2K]
Use KE= 1/2mv^2
So... 
50,000=(.5)(1,000)v^2
50,000=500 x v^2
Divide 500 on both sides 
100 = v^2 
Square root both sides to get rid of v^2 
Therefore v = 10 m/s
4 0
3 years ago
Read 2 more answers
How many million Christmas trees were sold in the year 2000?
Sergio039 [100]

Explanation:

Christmas tree production occurs worldwide on Christmas tree farms, in artificial tree factories and from native strands of pine and fir trees. Christmas trees, pine and fir trees purposely grown for use as a Christmas tree, are grown on plantations in many western nations, including Australia, the United Kingdom and the United States. In Australia, the industry is relatively new, and nations such as the United States, Germany and Canada are among world leaders in annual production.

Great Britain consumes about 8 million trees annually, while in the United States between 35 and 40 million trees are sold during the Christmas season. Artificial Christmas trees are mostly produced in the Pearl River delta area of China. Christmas tree prices were described using a Hotelling-Faustmann model in 2001, the study showed that Christmas tree prices declined with age and demonstrated why more farmers do not price their trees by the foot. In 1993, economists made the first known demand elasticity estimates for the natural Christmas tree market.

5 0
3 years ago
Given A=125.0=0.4 and 25.0=0.1 calculate A-B<br><br><br><br><br>​
kicyunya [14]

Answer: Find an answer to your question given A=125.0=0.4 and 25.0=0.1 calculate A-B​

Explanation:

6 0
2 years ago
What is the oldest animal on earth?
Lilit [14]

Answer:

e3f3ewfeewfewgwgewggegegeggegeggege

Explanation:

6 0
3 years ago
Read 2 more answers
Other questions:
  • The three types of nuclear radiation<br>​
    8·1 answer
  • The net force on a rock is 250 newtons downward. The rock accelerates at a rate of 10 m/s2. What is the rock's mass?
    14·1 answer
  • describe how you can use a compass needle to determine the direction of a magnetic field at a given location
    15·1 answer
  • Water is pumped steadily out of a flooded basement at a speed of 5.4 m/s through a uniform hose of radius 0.83 cm. The hose pass
    8·1 answer
  • You place an ice cube of mass 7.50×10−3kg and temperature 0.00∘C on top of a copper cube of mass 0.540 kg. All of the ice melts,
    9·1 answer
  • If Scoobie could drive a Jetson's flying car at a constant speed of 450.0 km/hr across oceans and space, approximately how long
    5·1 answer
  • Select all that apply so it’s not just one answer. please and thanks :))
    6·1 answer
  • Which wavelength of the electromagnetic spectrum are shorter than visible light and carry more energy
    13·1 answer
  • Suppose the spark plug on a heat engine is not functioning properly which statement best explains how this will affect the engin
    5·2 answers
  • You get hit in the head with a baseball as it is falling. What are the action and reaction forces?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!