What is the displacement of a runner who is running at 0.5km/h for 3 hours due north

What is the radius of an automobile tire that turns with a period of 0.091 s and has a linear

faust18 [17]

Answer:

1) The radius of the tire is approximately 0.28966 meters

2) The centripetal force is the force that keeps a body moving on a circular path

Explanation:

1) The linear speed of the automobile tire = 20.0 m/s

The period with which the tire turns = 0.091 s

The period = The time it takes to make a complete turn

Therefore;

The number of turns in 1 second = 1/0.091 ≈ 10.989 turns

The distance covered with 10.989 turns, assuming no friction = 10.989 × The circumference of the tire

∴ The distance covered with 10.989 turns, assuming no friction = 10.989 × 2 × π × Radius of the tire

From the speed of the car, 20.0 m/s, we have;

The distance covered in 1 second = 20.0 meters

Therefore;

10.989 × 2 × π × Radius of the tire = 20.0 meters

Radius of the tire = (20.0 meters)/(10.289 × 2 × π) ≈ 0.28966 meters

The radius of the tire ≈ 0.28966 meters

2) The centripetal force is the force required to maintain the curved motion of an object, and having a direction towards the center of the rotary motion.

The centripetal force is given by the formula, $F = \dfrac{m \cdot v^2}{r}$

Where;

F = The centripetal force

m = The mass of the object

v = The linear velocity of the object

r = The radius of the rotational motion.

3 0

2 years ago

The three forces acting on a hot-air balloon that is moving vertically are its weight, the force due to air resistance and the u

Aleksandr [31]

Let
upthrust = T
weight = W = mg
Air resistance = F

When balloon is descending, air resistance acts upwards (positive)
By Newton's first law, the net force on the balloon is zero, or
T+F-W=0......................(1)

Let w=weight of material dumped so that balloon now travels upwards at constant speed.
Air resistance acts against motion, namely downwards.
The Newton's equation now reads
T-F-(W-w)=0................(2)

Subtract (2) from (1)
T+F-W - (T-F-(W-w)) = 0
Solve for w
w=2F, or
the WEIGHT of material to be released equals twice the resistance of air.

3 0

2 years ago

A system delivers 1275 j of heat while the surroundings perform 855 j of work on it. calculate ∆esys in j.

kakasveta [241]

The first law of thermodynamics says that the variation of internal energy of a system is given by:
$\Delta U = Q + W$
where Q is the heat delivered by the system, while W is the work done on the system.

We must be careful with the signs here. The sign convention generally used is:
Q positive = Q absorbed by the system
Q negative = Q delivered by the system
W positive = W done on the system
W negative = W done by the system

So, in our problem, the heat is negative because it is releaed by the system:
Q=-1275 J
while the work is positive because it is performed by the surrounding on the system:
W=+855 J

So, the variation of internal energy of the system is
$\Delta U = -1275 J+855 J=-420 J$

6 0

2 years ago

A string is wrapped around a pulley with a radius of 2.0 cm and no appreciable friction in its axle. The pulley is initially not

stiks02 [169]

Answer:

2

Explanation:

2

5 0

2 years ago

Read 2 more answers

Which of the following statements is/are true? Check all that apply. Check all that apply. Power is the rate at which energy is

AlladinOne [14]

Answer:

True statements:

Power is the rate at which work is done.

Power is the rate at which energy is transformed.

The SI unit of power is watt.

A person is limited in the total work he or she can do by the rate at which energy can be transformed.

Explanation:

The above statements are true.

1. Power is defined as the rate at which work is done.

2. Power is the rate at which energy is transformed. Whenever energy changes its form, or moves from one place to another, the rate at which it makes those changes is described as power.

3. The SI Unit of power is watts. If 1 joule of energy is converted by an object in 1 second then its power is called one watt.

So, the statement<em> 'the SI unit of power is the horsepower' is</em> false.

4. A person is limited in the total work he or she can do by the rate at which energy can be transformed i.e, his power. He is not only limited by the total energy required.

So, the statement <em>'A person is limited in the total work he or she can do only by the total energy required'</em> is not completely true.

5 0

2 years ago