Martha's mass is 50 kg. Timmy's mass is twice as much. To reach to the first floor, Timmy took the stairs while Martha climbed up the ladder. Who did more work?

Acar of mass m goes around a banked curve of radius r with speed v. if the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to 101) a) mv2/r b) mg/2. d) mg e) tan[v2/(eg)]

Awave travels at a speed of 5.2 m/s. if the distance between crests is 0.40 m, what is the frequency of the wave? use f=v/wavelength a. 13 hz b. 2.1 hz c. 0.077 hz d. 5.6 hz

Lightning is an example of what phenomenon? a release of a large amount of energyan absorption of a large amount of energya natural electric circuita natural electric current