TIL-I Practice Exam Phy #1

A dumbbell with a mass of 2kg falls from 80m. The speed of the dumbbell when it touches the ground would be:

• 10m/s

• 20m/s

• 30m/s

• 40m/s

• 50m/s

When a point-like particle ,with no initial velocity, is dropped from top of a building with 180m height and it reaches the ground with the velocity of V. However the particle hits a balcony with a height of 100m. With what speed would the particle touch the ground?

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Two objects (A and B) have the same mass but their specific heats are c_A=xc_B. Temperature change of A and B are equal when A absorbs 250J and B absorbs 50J. What is x?

• 1/5

• 5

• 1

While moving to his new house, Mark needs to move his desk to his room upstairs. To do this he has two planks of wood he can use as an inclined plane. One of the planks is longer and has a smaller slope and the other plank is shorter and has a bigger slope. Mark will move the desk at a constant and an equal speed for both situations, so which plank would require him to exert more power? (Friction is negligible.)

• Shorter plank since it takes less time

• Longer plank since it takes more time

• Both situations power is equal since the change in energy is equal

• Since friction is neglected, we cannot compare the power

• None of the answers are correct

• 0

• 19

• 11

• -5

• 8

What is the SI unit of luminous intensity?

• ampere

• candela

• lumen

• coulumb

• photon

Two point charges, +5 C and -3 C, are placed 20 cm apart in a vacuum.

Calculate the electric force q (which has a charge +1C) at the midpoint. (Assume k=1)

• 200

• 800

• 0

• -80

• 20

For a non-ideal gas, which of the following is true about temperature of the gas (T)?

• Temperature in gases is associated with the average kinetic energy of the gas molecules.

• All gases reach absolute zero at the same rate.

• Temperature would increase if we doubled the amount of mol.

• Decrease in temperature always leads to a decrease in volume for all gases.

Which of the following is true for a Simple Harmonic Motion:

• Velocity reachs its maximum while displacement is maximum.

• Acceleration is always opposite in direction with speed.

• Restoring force is always aims for the equilibrium

• Period of a spring would be proportional to mass of the string and the length of the string.

• All periodic motions are examples of simple harmonic motion.

Two lamp cables have the same lenght but different cross-sectional areas (S₁ and S₂). What is the relationship between their resistance (R₁ and R₂) while 4S₁ = S₂?

• R₁ = R₂

• 4R₁ = 5R₂

• 2R₁ = R₂

• R₁ = 2R₂

• R₁ = 4R₂