The answer is a.12.5kg because i just did the test and it was correct.
hope this helps
2.39 Watts roughly since watts is joules per second it’s just 910j/380s
The initial velocity of the ball is 1.01 m/s
Explanation:
The motion of the ball rolling off the desk is a projectile motion, which consists of two independent motions:
- A uniform horizontal motion with constant horizontal velocity
- A vertical accelerated motion with constant acceleration (
, acceleration due to gravity)
We start by analyzing the vertical motion: we can find the time of flight of the ball by using the following suvat equation

where
s = 1.20 m is the vertical displacement (the height of the desk)
u = 0 is the initial vertical velocity

t is the time of flight
Solving for t,

Now we analyze the horizontal motion. We know that the ball covers a horizontal distance of
d = 0.50 m
in a time
t = 0.495 s
Therefore, since the horizontal velocity is constant, we can calculate it as

So, the ball rolls off the table at 1.01 m/s.
Learn more about projectile motion:
brainly.com/question/8751410
#LearnwithBrainly
Answer:

Explanation:
Btu of British thermal unit is a unit of heat. The relation between btu/year and watts is given by :

So,
is equal to 11 kW. Hence, the correct option is (d).
Answer:
D. 130 J
Explanation:
The coefficient of performance for a machine that is being used to cool, is given by:

Here
is the heat removed from the cold reservoir, W is the work required, that is, the energy required to remove the heat from the interior of the house,
is the cold temperature and
is the hot temperature. Recall use absolutes temperatures(
). Replacing and solving for W:
