Black Hole

Basic

Moderate

Challenging

Difficult

Black Hole

Question 1 

Which of the following are two vector quantities?

1. Speed, Mass
2. Speed, Force
3. Velocity, Mass
4. Force, Velocity

Question 2 

Which of the following answer options has two vector and two scalar quantities?

1. Force, momentum, mass, acceleration
2. Kinetic energy, velocity, potential difference, displacement
3. Speed, potential energy, temperature, current
4. Charge, impulse, power, time

Question 3 

The vectors below represent the displacement of two cars.

What is the direction of S_{A}-S_{B}?

Question 4 

A particle is moving upwards in a straight line at constant speed. Which diagram represents the forces acting on this particle?

Question 5 

Which of the following is a vector quantity?

1. Electric current
2. Distance
3. Pressure
4. Electric field strength

Question 6 

A person swims across a river that is flowing east. In what direction does the person have to swim so that she only moves towards the south from her starting point?

Question 7 

Which of the following answer options includes three scalar quantities?

1. Mass, speed, weight, magnetic field strength
2. Acceleration, time, temperature, velocity
3. Electric current, electric field strength, displacement, charge
4. Gravitational potential energy, amplitude, momentum, power

Question 8 

A block of mass m is sliding down a frictionless slope. The angle that the slope makes with the horizontal is \beta. 

The normal reaction force that acts on the block is R. What is the resultant force on the block?

1. mgsin\beta
2. mgcos\beta
3. Rsin\beta
4. Rcos\beta

Question 9 

A biker travels at a constant speed of 8 m s^{-1} west during a minute and then at a constant speed of 6 m s^{-1} south during a minute. What is the average speed of the biker during these two minutes?

1. 5 m s^{-1}
2. 7 m s^{-1}
3. 10 m s^{-1}
4. 14 m s^{-1}

Question 10 

Two forces, X and Y, are represented by the following vectors:

Which vector represents Y – X?

Question 11 

Two perpendicular forces of magnitudes 9 N and 12 N act on an object. The magnitude of the resultant force on the object is:

1. 3 N
2. 11 N
3. 15 N
4. 21 N

Question 12 

A force of 10 N can be resolved along directions AB and AC, where AB and AC are perpendicular to each other. 

The component of the force in the AC direction is 6 N. What is the magnitude of the component along the AB direction?

1. 2 N
2. 4 N
3. 6 N
4. 8 N

Question 13 

Three forces with magnitudes A, B, and C lie in the same plane and act on an object. The object is in equilibrium. 

Which of the following equations is correct?

1. A = B + C
2. Asin\alpha = B
3. Csin\alpha = A - Bcos\alpha
4. Acos\alpha = C

Question 14 

A stone is thrown with initial velocity v at an angle \theta to the horizontal. The magnitude of the vertical component of the stone’s velocity is 10 m s^{-1}. 

What is the value of \theta?

1. sin^{-1}\left ( \frac{10}{v} \right )
2. sin^{-1}\left ( \frac{v}{10} \right )
3. cos^{-1}\left ( \frac{10}{v} \right )
4. cos^{-1}\left ( \frac{v}{10} \right )

Question 15 

Three forces, \overrightarrow{A}, \overrightarrow{B} and \overrightarrow{C}, act on object X as shown on the diagram. Object X moves at constant velocity. 

Consider the following three equations:

I. \overrightarrow{A} + \overrightarrow{B} = - \overrightarrow{C}

II. \left | \overrightarrow{B} \right |cos(\alpha) = \left | \overrightarrow{C} \right |cos\left ( \frac{\pi}{2} - \alpha \right )

III. \left | \overrightarrow{A} \right | = \left | \overrightarrow{B} \right |sin(\alpha) + \left | \overrightarrow{C} \right |cos(\alpha)

Which of these three equations are correct?

1. I and II only
2. I and III only
3. II and III only
4. I, II and III