The correct statement about nuclear fusion is the last one: "it produces nearly all the elements that are heavier than helium". Nuclear fusion is the process of combination of two smaller atoms into a larger one. It requires a high activation energy, which is reached in the stars. Elements from He to Iron were formed in the Sun, but larger elements require a higher energy and are formed inside supernovas.
Answer: 0.145 seconds
Explanation:
Given that Roger Clemens could routinely throw a fastball at a horizontal speed of 119.7 m/s. How long did the ball take to reach home plate 17.3 m away
Since the speed is horizontal
Using the formula for speed which is
Speed = distance/time
Where
Speed = 119.7 m/s
Distance covered = 17.3 m
Time is what we are looking for
Substitute all the parameters into the formula
119.7 = 17.3/ time
Make time the subject of formula
Time = 17.3 / 119.7
Time = 0.145 seconds.
Therefore, it will take 0.145 seconds to reach the home plates
Answer:
The driver's average velocity is 82.35 km/h.
Explanation:
Given:
The motion of the driver can be divided into 3 parts:
i. Displacement of the driver in 1.5 hours = 135 km
ii. Rest for 45 minutes.
iii. Displacement in next 2 hours = 215 km
The direction of motion remains same (east).
Now, total displacement of the driver is,
km.
Rest time is 45 minutes. Converting it to hours, we need to use the conversion factor
hour.
So, 45 minutes in hours is equal to
hours.
Now, total time taken for the complete journey is, 
Average velocity is given as:

Therefore, the driver's average velocity is 82.35 km/h
Explanation:
gravitational potential energy at the top of the hill, which transforms into kinetic energy as he moves bottom of the hill
that's mean potential energy transfoms into kinetic energy