Keiko is riding a skateboard 2 m/s, west. how long will it take her to reach a velocity of 8 m/s, west if her acceleration is 2 m/s2

Answer : The time taken will be 3 seconds.

Explanation :

By the 1st equation of motion,

...........(1)

where,

v = final velocity = 8 m/s

u = initial velocity  = 2 m/s

t = time = ?

a = acceleration =

Now put all the given values in the above equation 1, we get:

Hence, the time taken will be 3 seconds.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.