quiz

Tamkeen 11A Physics Term 3 EOT Review

By Matthew Everest

​Cuboid centre of mass =
(w/2 , h/2. d/2)

UNIFORM ONLY

Multiple Choice

Find the centre of gravity of this uniform mass solid shape on the left.

(x positive is right, y positive is up, z positive is more into the screen)

Make the front bottom right corner closest to you the reference point / origin

• (0.3,0,3,0,6) m

• (0.3, 0.15, 0.15) m

• (60, 30, 30) cm

• (15, 30, 15) cm

Multiple Choice

A 5kg mass and a 3kg mass are separated by 4m. Find the distance from the 3kg mass to the centre of mass of the system.

• 1.5m

• 2.5m

• 3m

• 2m

Multiple Choice

Find the polar coordinate of (1, -1) meters (find angle in degrees) $$r\ =\ \sqrt[]{x^2+\ y^2\ }$$

$$\theta\ =\ \tan^{-1}\left(\frac{y}{x}\right)$$

• $$\left(\sqrt[]{2\ },\ 45\degree\right)$$

• $$\left(2\ ,\ 45\degree\right)$$

• $$\left(\sqrt[]{2},\ -45\degree\right)$$

• $$\left(\ 2\ ,\ -45\degree\right)$$

​CHECK IF YOUR CALCULATOR IS IN RADIANS OR DEGREES WHEN USING TAN!

Multiple Choice

What is the unit for angular velocity?

• m/s

• m

• degrees/s

• rad/s

Multiple Choice

The angular velocity of a car wheel is the same everywhere along the wheel regardless of the location of the part of the wheel whne spinning. Which part of the wheel has a higher tangential velocity?

• the inside middle of the wheel

• the outside tyre of the wheel

• its the same everywhere

• i don't know... sad times

Multiple Choice

which diagram represents a circular motion with increasing angular velocity?

• none of these

Multiple Choice

Find the magnitude of the acceleration of a particle in circular motion with an angular velocity of 4.0rad/s and an angular acceleration of 5.0rad/s² and a constant radius of travel of 20cm.

• 3m/s²

• 32m/s²

• 333m/s²

• 34m/s²

Multiple Choice

A ball attached to the end of a string is swung around in a circular path of radius r. If the radius is double and the linear speed is kept constant, what will happen to the centripetal acceleration?

• double (x2)

• half (/2)

• stay the same

• quadroople (x4)

Multiple Choice

There are many types of force which can be the centripetal force, which one is the main centripetal force for driving a car around in a horizontal flat corner?

• gravity force

• weight force

• tension force

• friction force

Multiple Choice

when can we use the kinematics equations

• when angular acceleration is increasing

• when angular acceleration is constant

• when angular accelelration is decreasing

• i dont know

Multiple Choice

A speedway turn, with radius of curvature 500, is banked at an angle 20 degrees above the horizontal . What is the fastest speed at which to take the turn if the track surface is covered in ice and there is almost 0 friction?

• 41.6 m/s

• 38.2 m/s

• 64.9 m/s

• 12.5 m/s

Multiple Choice

the moment of inertia of a mass CANNOT depend on...

• shape

• radius

• mass

• axis of rotation

• frequency

Multiple Choice

If a force of F newtons pushes on a spanner perpendicular to it as shown on the left. What will happen to the torque on the bolt applied by the hand it it gets twice as close to the bolt and pushes with twice as much force?

• x4

• x2

• stays the same

• / 2

Multiple Choice

what is the equation to find the X coordinate of the centre of mass of a point particle system of three masses?

• $$X\ =\ \frac{x_1m_1+x_2m_2+x_3m_3}{m_1+m_2+m_3}$$

• $$X\ =\ \ \ \frac{\sum_x^y\ m}{xm\ +xm\ +xm}$$

• $$Y\ =\ \frac{y_1m_1+y_2m_2+y_3m_3}{m_1+m_2+m_3}$$

Multiple Choice

Find the distance a car moves around a corner with a radius of arc of turn of 30m moving through an angle of 40 degrees (degree to radian is x $$\frac{\pi}{180}$$ )

• 20.9m

• 31.1m

• 23.8m

• 30.0m

Multiple Choice

Find the tangential velocity of a 0.5m radius car wheel rotating at 600rpm.

steps:

step 1: Divide rpm by 60 to get = f

step 2: $$\omega=2\pi f$$

step 3: $$v=\omega r$$

• 20 $$\pi$$ m/s

• 10 $$\pi$$ m/s

• 5 $$\pi$$ m/s

• $$\pi$$ m/s

Multiple Choice

The net force is equal to what during any uniform circular motion?

• F_net = F_c

• F_net = mass x gravity

• Fnet = gravity

• Fnet = Tension - mg

​Fnet is the centripetal force! they are the same in uniform circular motion!!!

Multiple Choice

determine the moment of inertia for 3 boys weighing 60kg, 45kg, and 80kg all sitting at on the SAME edge at different points of a rotating massless stage with a radius of 12m.

• 1300kg.m²

• 1500kg.m²

• 1200kg.m²

• 1100kg.m²

Any questions?