Which vector is the sum of vectors a and ? b а O A. B. C.

What is the angular displacement of the wheel between t = 5 s and t = 15 s?

Mkey [24]

The question seems incomplete. The complete text is:

a)What is the angular displacement of the wheel between t = 5 s and t = 15 s

b)What is the angular velocity of the wheel at 15 s

And it refers to the attached figure.

a) 25 rad

The graph shown represent the angular position of the wheel at different times.

Therefore, we can simply calculate the angular displacement between two times by calculating the difference between the angular position at t2 and the angular position at t1.

At $t_1 = 5 s$ , the angular position from the graph is $\theta_1 = 100 rad$

At $t_2 = 15 s$ , the angular position from the graph is $\theta_2 = 125 rad$

Therefore, the angular displacement is

$\Delta \theta= \theta_2 - \theta_1 = 125-100 = 25 rad$

2) -5.0 rad/s

For a angular displacement vs time graph, the angular velocity at any time is simply equal to the slope of the curve at that time.

Here we want to calculate the angular velocity at t = 15 s, so we have to calculate the slope at that time.

By noting that the slope is constant in the last part of the motion, we find that the slope between 10 s and 20 s is:

$\frac{\Delta \theta}{\Delta t}=\frac{100 rad - 150 rad}{20 s - 10 s}=-5.0 rad/s$

This slope is constant between 10 s and 20 s, so the angular velocity of the wheel at t = 15 s

$\omega = -5.0 rad/s$

5 0

3 years ago

A bar-magnet with magnetic moment 2.5 Am^2 is placed in a homogeneous magnetic field (of 0.1 T that is directed along the z-axis

Angelina_Jolie [31]

Answer:

1)

Force on bar magnet = 0

Torque on bar magnet = 0

2)

Force on bar magnet = 0

Torque on bar magnet = 0.177 Nm

3)

Force on bar magnet = 0

Torque on bar magnet = 0.25 Nm

Explanation:

Part 1)

net force on bar magnet in uniform magnetic field is always zero

Torque on bar magnet is given as

$\tau = MBsin\theta$

when bar magnet is inclined along z axis along magnetic field

then we will have

$\tau = MBsin0 = 0$

Part 2)

net force on bar magnet in uniform magnetic field is always zero

Torque on bar magnet is given as

$\tau = MBsin\theta$

when bar magnet is pointing 45 degree with z axis then we will have

$\tau = MBsin45$

$\tau = (2.5)(0.1)sin45$

$\tau = 0.177 Nm$

Part 3)

net force on bar magnet in uniform magnetic field is always zero

Torque on bar magnet is given as

$\tau = MBsin\theta$

when bar magnet is pointing 90 degree with z axis then we will have

$\tau = MBsin90$

$\tau = (2.5)(0.1)sin90$

$\tau = 0.25 Nm$

8 0

3 years ago

U"LL GET 24PTS IF U HELP ME

gavmur [86]

Answer: When your bike stops from brakes.

Explanation: Force and friction affect our daily lives in numerous amounts of ways. For instance, when a football is kicked, it moves faster later after some time its force decreases due to friction. A common example of friciton is when a bike stops. When the brakes are applied the friction on the pads cause the bike to stop.

6 0

3 years ago

starting from a stop a traffic signal, a car speeds up to 20 m/s in 5 seconds. calculate the acceleration of the car.

Ira Lisetskai [31]

Answer:

5.867 m/s^2

Explanation:

Initial Speed > 0 m/s

Final Speed > 20 m/s

Time > 5 sec.

8 0

3 years ago

a bullet moving with a velocity of 100m/s pierce a block of wood and moves out with a velocityof 10 m/s.if the thickness of the

erma4kov [3.2K]

The emerging velocity of the bullet is 71 m/s.

The bullet of mass m moving with a velocity u has kinetic energy. When it pierces the block of wood, the block exerts a force of friction on the bullet. As the bullet passes through the block, work is done against the resistive forces exerted on the bullet by the block. This results in the reduction of the bullet's kinetic energy. The bullet has a speed v when it emerges from the block.

If the block exerts a resistive force F on the bullet and the thickness of the block is x then, the work done by the resistive force is given by,

$W=Fx$