Formula First!

A car decelerates from 20 m s^-1 until it stopped within 10 s. Which equation can you use to find the distance travelled by the car?

• s=ut+½at²

• v=u+at

• v²=u²+2as

• s=½(u+v)t

J=mv-mu

What does mv represent in the above equation?

• Final impulse

• Final impulsive force

• Final momentum

• Final velocity

Which of these is not a force?

• Tension, T

• frequency, f

• Pushing force, F

• Weight,W

W=Fs cos θ

According to the above equation, what does θ represent?

• projectile angle

• angle between W and F

• angle between W and s

• angle between F and s

U_s=½kx²

In the equation above, what does k represent?

• Coulomb's constant

• Boltzmann's constant

• force constant

• thermal conductivity

A ball tied with a string is spun vertically by a boy. At the top on the circle, where is the direction of the acceleration experienced by the ball?

• towards the boy

• parallel to the tangential velocity

• tangential to the centripetal force

• upwards

E=½kA²

According to the equation above, where does the total energy becomes zero?

• At equilibrium

• Halfway between equilibrium and amplitude

• At maximum displacement

• Never

A 100 g pendulum bob tied with a 1 m string performs simple harmonic motion. Which equation can you use to find how long it takes for the bob to complete 1 cycle?

• v=Aω cos ωt

A rubber duck moves vertically when a girl jumps into a pool of water. Which equation can you use to determine how fast the speed of the rubber duck?

A 1 m string produced standing wave. Which equation can you use to find the amplitude of the wave 20 cm from the equilibrium?

• y=2A cos kx