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
SVETLANKA909090 [29]
2 years ago
13

a body of mass 0.2kg is whirled round a horizontal circle by a string inclined at 30 degrees to the vertical calculate <br /&

gt;a. tension in the string<br />b. speed of the body in the circle<br />​
Physics
1 answer:
Katen [24]2 years ago
8 0

Answer:

a)  T = 2.26 N, b) v = 1.68 m / s

Explanation:

We use Newton's second law

Let's set a reference system where the x-axis is radial and the y-axis is vertical, let's decompose the tension of the string

        sin 30 = \frac{T_x}{T}

        cos 30 = \frac{T_y}{T}

        Tₓ = T sin 30

        T_y = T cos 30

Y axis  

       T_y -W = 0

       T cos 30 = mg                     (1)

X axis

        Tₓ = m a

they relate it is centripetal

        a = v² / r

we substitute

         T sin 30 = m\frac{v^2}{r}            (2)

a) we substitute in 1

         T = \frac{mg }{cos 30}

         T = \frac{ 0.2 \ 9.8}{cos  \ 30}

         T = 2.26 N

b) from equation 2

           v² = \frac{T \ sin 30 \ r}{m}

If we know the length of the string

          sin 30 = r / L

          r = L sin 30

we substitute

          v² = \frac{ T \ sin 30 \ L \ sin 30}{m}

          v² = \frac{TL \ sin^2  30}{m}

For the problem let us take L = 1 m

let's calculate

          v = \sqrt{ \frac{2.26 \ 1 \ sin^230}{0.2} }

          v = 1.68 m / s

You might be interested in
two identical eggs are dropped from the same height. The first eggs lands on a dish and breaks, while the second lands on a pill
Nataly_w [17]

Answer:

The height is the same

Explanation:

Because they were at the same height but they fell at different velocities

5 0
3 years ago
A constant net torque is applied to an object. Which one of the following will NOT be constant?
love history [14]

Answer:

B) Angular velocity

Explanation:

The equivalent of Newton's second law for the rotational motions can be written as:

\tau = I \alpha

where

\tau is the net torque applied to the object

I is the moment of inertia

\alpha is the angular acceleration

From the formula we see that when a constant net torque \tau is applied, then the object also has a constant angular acceleration, \alpha.

But we also know that

\alpha = \frac{d\omega}{dt}

where \omega is the angular velocity: so, a constant angular acceleration means that the angular velocity of the object is changing, so the correct answer is

B) Angular velocity

(moment of inertia and center of gravity do not change since they only depend on the mass and the geometry/shape of the object, which do not change)

7 0
3 years ago
A man, a distance d=3~\text{m}d=3 m from a target, throws a ball at an angle \theta= 70^\circθ=70 ​∘ ​​ above the horizontal. If
lbvjy [14]

Answer:

The ball doesn't strike the building because it strikes the ground at d=1.62 meters.

Explanation:

V= 5 m/s < 70º

Vx= 1.71 m/s

Vy= 4.69 m/s

h= Vy * t - g * t²/2

clearing t for the flying time of the ball:

t= 0.95 s

d= Vx * t

d= 1.62 m

4 0
3 years ago
What are the factor that affect the efficiency of a pulley​
alukav5142 [94]

Answer:

Tension in the chains - In a chain drive, technically, you have a closed-chain (which has no end) going around 2 pulley or gears; looking closely you have 2 parallel chains going in opposite direction. If kept in horizontal direction, the one below the other is the slack side and the other the tight side. The tension on the upper or tight side is more than the slack side. So you need to keep in mind to keep your chain drive tight so that there is no loss or rotation or lags.

Sizes of the pulley/gear - The chain will be warped around a pair of pulley or gear. The sizes of these pulley/gear will also determine the efficiency of the chain drive (consider one big and one small)

Number of pulley/gear - If the number of pulley/gear is more and chain wrapped on it with little complexity will result in decrease in efficiency because of extra tension.

Length of the chain drive - You cannot have much too long chain drive. It will make your slack side more heavy because the end are further away. You have to apply more power and possibilities of lag increases decreasing efficiency. In an ideal situation, this won't happen, but this world isn't ideal.

Friction between chains & pulley/gear - If you have studied gears (involving its teeth), you will come to know that there is friction offered on the two meeting surfaces.

Angle of contact - This would have been explained better with a diagram. Although, if you are familiar with the terms you won't have difficulty understanding. Angle of contact is the angle the chain forms with the pulley/gear at the point of contact with the center of the pulley. The angle of contact should not be too small, or else the things will be slippery.

Explanation:

8 0
3 years ago
What is the magnitude of a vector with components (15 m, 8 m)?
il63 [147K]
The answer is 17 m because you have to add the 15 m and the 8 m together to get the answer so it will be like this 17x17 = 15x15 + 8x8 got it?
8 0
3 years ago
Read 2 more answers
Other questions:
  • During a lab, a student tapes a ruler to a lab table and sets the ruler in motion. A laser detector pointed at the ruler records
    8·1 answer
  • How much time does it take Mrs. Spencer to travel 240meters at a speed of 80meters per second?​
    15·1 answer
  • An athlete is working out in the weight room.he steadily holds 50 kilograms above his head for 10 seconds which statement is tru
    5·1 answer
  • What family does the fox come from?
    6·1 answer
  • 4) Astronomers use tiny wobbles of distant stars to detect the presence of planets orbiting those stars. This occurs because the
    10·1 answer
  • Renewable resources can be
    14·1 answer
  • Why are frames of reference important for motion
    10·1 answer
  • What is the difference between an energy pyramid and a biomass pyramid?
    8·1 answer
  • A 1.3-kg ball is attached to the end of a 0.8-m string to form a pendulum. This pendulum is released from rest with the string h
    10·1 answer
  • 1. True or False: Since the 1990s the USA has been working with Russia and
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!