Calculate the kinetic energy of a bicyclist traveling at 11 m/s. The total mass of the cyclist and the bike is 74 kg.

4477J

Explanation:

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

0·77 m

Explanation:

Given

Spring constant = k = 790 N/m

Equilibrium length of the spring = 48 cm = 0·48 m

Force applied = 230 N

Let the x m be the length of the spring when 230 N of force is applied on it

Spring force that is acting will be k × (x - 0·48)

When applied force is 230 N, the spring force will also be equal to 230 N as there will be equilibrium

∴ k × (x - 0·48) = 230

790 × (x - 0·48) = 230

x = (230 ÷ 790) + 0·48

x = 0·29 + 0·48

∴ x = 0·77 m

∴ Length of the spring when 230 N of force is applied to stretch it = 0·77 m