Physics-test 9

A block is released from the top of a rough incline with an initial speed of 2 m/s as shown below. The coefficient of kinetic friction between the block and the incline is 0.6. How much work is done by the normal force when the block reaches the bottom of the incline?

0 j

An object covers the circumference of a circular track of radius R = 20 m in 30 minutes. What is the average velocity of the object?

0 m/s The total displacement of the object is zero since it ends where it started.

A string on a guitar has a length of 4 m. If the velocity of a standing wave travelling through the string is 400 m/s at the second harmonic, what is the frequency of the wave at the same harmonic?

100 Hz

An object of mass 5 kg has a linear momentum of 15 kg.m/s. What is the kinetic energy of the object?

22.5 J

5 N of force is exerted on a spring, and it compresses by 0.2 m. What is the spring constant?

25 n/m

An astronaut lands on planet Petra whose radius and mass are each three times that of Earth. If the astronaut weighs 900 N on Earth, what will be his weight on the surface of planet Petra?

300 n

3 blocks M, N, and P rest on a table as shown below. The weight of each block is shown. What is the force exerted by block M on block N?

40 N

A stone is attached to a string that is 0.4 m long. If it is swung horizontally and completes 5 revolutions per second, what is the centripetal acceleration experienced by the stone?

40 pie2 m/s^2

If the surface of the incline shown below is frictionless, with what speed will the block reach the bottom if its speed at the top of the incline is 2 m/s?

8 m/s

3 blocks M, N, and P rest on a table as shown below. The weight of each block is shown. What is the force exerted by block P on block N?

90 N

Which of the following could be the optical device shown below?

A diverging lens

Two objects collide and stick together following the collision. What type of collision did they engage in?

A perfectly inelastic collision

Which of the following is an example of a longitudinal wave?

A sound wave

The triple point of a substance is a point for which the temperature and pressure are such that _______________.

All the three phases; solid, liquid, and gas are in equilibrium

A net torque applied to a rigid body produces:

Angular acceleration

An object is placed in front of a convex lens and a magnified inverted real image is produced. Where is the object located?

At a distance between f and 2f

Which of the following free-body diagram best represents the forces acting on an astronaut in orbit around Earth?

C-The only force acting on the astronaut is the force of gravity due to the earth's pull.

An Ampere-hour is a unit of which of the following physical quantities?

Charge

The figure below shows a spring attached to a ceiling. If the mass attached to the spring is doubled, how will the mass equilibrium's position and frequency be affected?

Equilibrium position: Increased by a factor of 2. Frequency: Decreased by a factor of √2

Each of the following is a scalar quantity EXCEPT one. Which one is the EXCEPTION? A. Power [7%] B. Energy [6%] C. Pressure [4%] D. Force [83%]

Force

What is the total current delivered by the battery and the total power dissipated by the circuit below?

I = 0.17 A, P = 4.2 Watts

3 balls with identical masses m are attached to a vertical shaft S by 3 rigid massless rods and are free to rotate about S. What is the total moment of inertia of the 3 balls?

I = 14M kg.m2

An ideal battery of constant voltage V supplies current to a circuit that has total resistance R. If the total resistance is doubled, what happens to the rate at which the energy is dissipated by the circuit?

It halves

A sound wave travels through air with a speed of 340 m/s and through glass with a speed of 3400 m/s. What happens to the wavelength of a sound wave as it travels from air to glass?

It increases by a factor of 10

When a spherical ball is submerged in water, it experiences a buoyancy force FB. If the radius of the ball is doubled, how will the buoyancy force be affected?

It increases by a factor of 8

Which of the following most accurately describes the pressure of a gas?

It is the force per unit area exerted by the gas on the walls of the vessel within which it is contained

A ball is tossed straight up vertically. Which of the following statements is true regarding the ball when it is at its highest point?

Its velocity will be equal to zero

An adiabatic process is a process in which

No heat is gained or lost by the gas

White light is shone through a red filter, followed by a green filter. What colour would you see on the other side?

No light

An object of height 2 cm is placed 30 cm in front of a converging lens with a radius of curvature of 20 cm. Which of the following is true about the image formed by the lens?

Real, inverted, height = 1 cm

young's modulus is defined as the ratio of the force per unit area to:

The fractional change in length

A plate is held upright between a screen and a candle as shown in the diagram below. A shadow is cast on the screen. What will happen to the shadow as the plate is moved toward the candle?

The shadow will get larger

What is the escape velocity of an object with mass m at the surface of Earth?

Ve=Sqrt 2Gm/R

Which of the following graphs correctly represents the acceleration of an object moving with a constant velocity?

When an object moves with constant velocity, its acceleration is zero. Answer: D

What happens to the gravitational force between two objects if the mass of one object is doubled, and the distance between the centers of the objects is doubled?

it halves

What is the force of gravity equal to?

mg

An object is located 2 m away from a concave lens with a focal length of 0.5 m. Will the image be upright or inverted and where would it be located?

upright, in front of the lens

Water flows through a cylindrical pipe with varying cross-sections as shown below. If the radius of section A is twice the radius of section B, what is the speed of water vB at section B?

vB = 4vA

The siren on a firetruck emits a tone of 200 Hz. If the speed of sound in air is 340 m/s, what is the wavelength of the sound wave?

λ = 1.7 m