10 auto-graded practice problems. Select an answer, submit, and review the explanation.
Mechanics: Equations of Motion, Projectiles, Forces, and Energy
easy
A car accelerates uniformly from rest at 3 m/s squared for 8 seconds. Using the equations of motion, what distance does the car travel during this time?
medium
A projectile is launched horizontally from a cliff edge at 15 m/s and takes 4 seconds to reach the ground. How far horizontally from the cliff base does the projectile land, and what is its vertical velocity just before impact?
hard
A 5 kg object is pulled across a horizontal surface with a force of 40 N at an angle of 30 degrees above the horizontal. If the coefficient of friction is 0.3, what is the acceleration of the object?
Dynamics and Space: Gravitation, Circular Motion, and Impulse
medium
A satellite orbits the Earth at an altitude where the gravitational field strength is 4.5 N/kg. If the satellite has a mass of 800 kg and orbits at a radius of 8.0 x 10 to the power of 6 metres from the Earth\'s centre, what is the centripetal force acting on the satellite?
hard
A 0.15 kg cricket ball travelling at 30 m/s is hit by a bat and returns in the opposite direction at 20 m/s. If the contact time between bat and ball is 0.05 seconds, what is the average force exerted on the ball by the bat?
Electricity: Ohm’s Law, Kirchhoff’s Laws, and Circuits
medium
A circuit contains a 12 V battery with internal resistance 0.5 ohms connected to an external resistor of 5.5 ohms. What is the current in the circuit and the terminal potential difference (p.d.) across the battery?
easy
In a series circuit with two resistors of 4 ohms and 6 ohms, a current of 2 A flows. What is the potential difference across each resistor and the total potential difference supplied by the battery?
medium
In the UK mains supply, the root mean square (r.m.s.) voltage is 230 V and the frequency is 50 Hz. What is the peak voltage of the supply and what is the time for one complete cycle?
Particles and Waves: Photoelectric Effect and Interference
hard
In the photoelectric effect, light of frequency 8.0 x 10 to the power of 14 Hz is incident on a metal surface with a work function of 4.0 x 10 to the power of minus 19 joules. The maximum kinetic energy of the emitted photoelectrons is approximately 1.30 x 10 to the power of minus 19 J. Which statement best explains this result?
medium
In a double-slit interference experiment, light of wavelength 600 nm produces bright fringes 3.0 mm apart on a screen. If the slit-to-screen distance is 1.5 m, what is the slit separation?