Acyclist is riding along at a constant velocity of 15 m/s. he then accelerates at a uniform rate of 0.50 m/s2 over a distance of 64 m. how long did he accelerate for?

Cyclist will take 4 seconds to travel 64 meter.

Explanation:

 We have equation of motion, , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

 In this case initial velocity = 15 m/s, acceleration = 0.50 , we need to calculate time when displacement = 64 meter.

 Substituting

 t = 4 seconds or t = -64 seconds(which is not possible).

So he will take 4 seconds to travel 64 meter.

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.