Answer:
Work done, W = 6153.31 Joules
Explanation:
It is given that,
Weight of piano, W = F = 7382 N
It is pushed 2.16 meters friction less plank
The angle with horizontal, 
When the piano slide up plank at a slow constant rate. The y component of force is taken into consideration. The net force acting on it is given by :
Work done is given by :
W = 6153.31 Joules
So, the work done in sliding the piano up the plank is 6153.31 Joules. Hence, this is the required solution.
Answer:
Ball hit the tall building 50 m away below 10.20 m its original level
Explanation:
Horizontal speed = 20 cos40 = 15.32 m/s
Horizontal displacement = 50 m
Horizontal acceleration = 0 m/s²
Substituting in s = ut + 0.5at²
50 = 15.32 t + 0.5 x 0 x t²
t = 3.26 s
Now we need to find how much vertical distance ball travels in 3.26 s.
Initial vertical speed = 20 sin40 = 12.86 m/s
Time = 3.26 s
Vertical acceleration = -9.81 m/s²
Substituting in s = ut + 0.5at²
s = 12.86 x 3.26 + 0.5 x -9.81 x 3.26²
s = -10.20 m
So ball hit the tall building 50 m away below 10.20 m its original level
True
Variables is changing. It is any factor, trait or condition that can exist in differing amounts or types. An experiment has three types: Independent, Dependent and Controlled.
The train would need the greatest amount of force due to weight! If you think of it, a baseball won't need much force to stop it, but if you have a heavy train, it will need excessive force to stop the train. The answer would be #3
I hope this answer helps!
Sorry if it doesn't make sense, as I don't know that much about physics! I am just thinking of what makes sense.
