Answer:
This is known as a Galilean transformation where
V' = V - U
Where the primed frame is the Earth frame and the unprimed frame is the frame moving with respect to the moving frame
V - speed of object in the unprimed frame
U - speed of primed frame with respect to the unprimed frame
Here we have:
V = -15 m/s speed of ball in the moving frame (the truck)
U = -20 m/s speed of primed (rest) frame with respect to moving frame
So V' = -15 - (-20) = 5 m/s
It may help if you draw a vector representing the moving frame and then add
a vector representing the speed of the ball in the moving frame.
Answer:
Speed of the speeder will be 28 m/sec
Explanation:
In first case police car is traveling with a speed of 90 km/hr
We can change 90 km/hr in m/sec
So 
Car is traveling for 1 sec with a constant speed so distance traveled in 1 sec = 25×1 = 25 m
After that car is accelerating with
for 7 sec
So distance traveled by car in these 7 sec

So total distance traveled by police car = 224 m
This distance is also same for speeder
Now let speeder is moving with constant velocity v
so 
v = 28 m/sec
Answer:
C.) 1
Explanation:
1 is the closest to 1.04
Also you never want to go above your prescription amount
Answer:
T₂ = 20.06 ° C
Explanation:
Given
P = 90 kg, T₁ = 20 ° C, h = 30 m, c = 1.82 kJ / Kg * ° C
Using the formula to determine the final temperature of the water
T₂ = T₁ * P * h / Eₐ * c
The work done of the person to the water
Eₐ = 1000 kg / m³ * 5 m³ * 9.8 m / s²
Eₐ = 49000 N
T₂ = 20 ° C +[ (90 kg * 30m) / (49000 N * 1.82) ]
T₂ = 20.06 ° C
Answer:

Explanation:
In order to solve this problem, we mus start by drawing a free body diagram of the given situation (See attached picture).
From the free body diagram we can now do a sum of forces in the x and y direction. Let's start with the y-direction:



so:

now we can go ahead and do a sum of forces in the x-direction:

the sum of forces in x is 0 because it's moving at a constant speed.



so now we solve for theta. We can start by factoring mg so we get:

we can divide both sides into mg so we get:

this tells us that the problem is independent of the mass of the object.

we now divide both sides of the equation into
so we get:


so we now take the inverse function of tan to get:

so now we can find our angle:

so
