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3 years ago

1.Explain frame of reference. How is it different when you are riding inside a car or standing by the highway?

Physics

1 answer:

galben [10]3 years ago

8 0

Answer:

See explanation

Explanation:

A frame of reference simply refers to a set of coordinates which is used to determine the position and velocity of objects all the objects found in that particular frame. The person inside the car and standing by the highway are in different frames of reference.

Newtons first law of motion states that an object will continue to be at rest or in a state of uniform velocity until it is acted upon by an external force.

Newtons second law states that rate of change of momentum is directly proportional to the impressed force.

Newtons third law states that action and reaction are equal and opposite.

The action of applying brakes leads to an equal reaction of a sudden forward movement. Seat belts help to prevent the occupants of a car from being injured by the sudden stoppage of the car.

Force is simply defined as a push or pull.

Balanced forces do not lead to acceleration of a body but an unbalanced for leads to acceleration of a body.

strong nuclear force, electromagnetic force, weak nuclear force and gravity

Power is the rate of doing work while week is said to be done when the force applied moves a distance in the direction of the force. Power is defined as work/time.

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The stopwatch used by a student to measure velocity of a pulse in a slinky was of least count 0.1 second. He stops the stopwatch

sweet-ann [11.9K]

Least count of the pulse stopwatch is given by

$\Delta t = 0.1 s$

this means each division of the stopwatch will measure 0.1 s of time

After 3 journeys from one end to other we can see that total time that is measured here is shown by the clock as 52nd division

So here total time is given as

Time = (Number of division) (Least count)

now we will have

$T = 52 \times 0.1s$

$T = 5.2 s$

4 0

3 years ago

What is the torque τa about axis a due to the force f⃗ ? express the torque about axis a at cartesian coordinates (0,0)?

pentagon [3]

Answer:

$\tau_a = F a sin \theta$

Explanation:

The torque of a force is given by:

$\tau = F d sin \theta$

where

F is the magnitude of the force

d is the distance between the point of application of the force and the centre of rotation of the system

$\theta$ is the angle between the direction of the force and d

In this problem, we have:

$F$ , the force

$a$ , the distance of application of the force from the centre (0,0)

$\theta$ , the angle between the direction of the force and a

Therefore, the torque is

$\tau_a = F a sin \theta$

5 0

3 years ago

A skateboarder is skating back and forth on the halfpipe as seen below. As he skates his energy transforms from potential energy

egoroff_w [7]

Answer:

Friction and air resistance cause some of his kinetic energy to be “lost”. This makes him slow down.

Explanation:

The law of conservation of energy states that in absence of frictional forces, the mechanical energy of an object (given by the sum of its kinetic and potential energy) is conserved. In such a situation, the skateboarder would never stop his motion, because potential energy is continuously converted into kinetic energy and vice-versa, but the total energy remains the same so he would never stop.

In a real world, however, this is not true. In fact, in a real world some frictional force are present, in particular:

- friction: this force is due to the contact between the skateboard and the surface of the halfpipe, and its direction is always opposite to the motion of the skateboarder

- Air resistance: this force is due to the resistance opposed by the molecules of air that the skateboarder meets during his motion, and its direction is also opposite to the motion of the skateboarder

This two forces are said to be non-conservative forces, which means that they cause some of the mechanical energy of the skateboarder to be "lost", in the sense that it is dissipated as heat and it is no longer available for the skateboarder.

Therefore, the correct option is

Friction and air resistance cause some of his kinetic energy to be “lost”. This makes him slow down.

7 0

3 years ago

A sinusoidal wave of angular frequency 1,203 rad/s and amplitude 3.1 mm is sent along a cord with linear density 3.9 g/m and ten

kobusy [5.1K]

Answer:

18.7842493212 W

Explanation:

T = Tension = 1871 N

$\mu$ = Linear density = 3.9 g/m

y = Amplitude = 3.1 mm

$\omega$ = Angular frequency = 1203 rad/s

Average rate of energy transfer is given by

$P=\dfrac{1}{2}\sqrt{T\mu}\omega^2y^2\\\Rightarrow P=\dfrac{1}{2}\sqrt{1871\times 3.9\times 10^{-3}}\times 1203^2\times (3.1\times 10^{-3})^2\\\Rightarrow P=18.7842493212\ W$

The average rate at which energy is transported by the wave to the opposite end of the cord is 18.7842493212 W

7 0

3 years ago

A mother and daughter press their hands together and then push apart while ice skating. Immediately after they push away from ea

kherson [118]

Answer:

Explanation:

The daughter moves with greater acceleration backwards because of her weight.

7 0

2 years ago

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