A space rocket accelerates uniformly from rest to 160ms^-1 upwards in 4.0s, then travels with a constant speed of 160ms^-1 for the next 5.0s. What is the initial acceleration of the rocket?

40 ms¯².

Explanation:

To solve this problem, we shall illustrate the question with a diagram.

The attached photo gives a better understanding of the question.

From the attached photo:

Velocity (v) = 160 ms¯¹

Time (t) = 4 secs.

Acceleration (a) =?

Acceleration (a) = Velocity (v) /time (t)

a = v/t

a = 160/4

a = 40 ms¯²

Therefore, the initial acceleration of the rocket is 40 ms¯².

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.