Answer:
(a) 
(b) 
 
Explanation:
mass, m = 2.3 kg 
vx = 40 m/s 
vy = 75 m/s 
(a) Angular momentum is given by 

Where, p is the linear momentum and r is the position vector about which the angular momentum is calculated. 
Here, 



So, the angular momentum 


(b) Here, 



 
        
             
        
        
        
Answer:
 0.64 m 
Explanation:
The first thing is calculate the center of mass of the system.

now multiplying every coordinate x by the mass of each object (romeo, juliet and the boat) and dividing all by the total mass  taking by reference the position of juliet.

X_cm = 1.4589 m
When the forces involved are internals, the center of mass don't change   
After the movement the center of mass remains in the same distance from the shore, but change relative to the rear of the boat.

X_cm= 2.10 m 
this displacement is how the boat move toward the shore.
2.10-1.46= 0.64 m 
 
        
             
        
        
        
He needs to measure when he draws the Simpson characters to make sure they are the same time each time he draws them
        
             
        
        
        
Answer:
a) Transverse and longitudinal
Explanation:
Depending on the medium in which the sound is traveling the wave can be longitudinal or transverse.
When traveling in fluids i.e., in liquids and gases the wave takes the form of a longitudinal wave. Longitudinal waves cause compression and rarefaction  of the fluid. 
When traveling in solids the wave takes the form of a transverse wave. Transverse waves leads to the formation of shear stresses in the solid.
 
        
             
        
        
        
Answer:
238.75⁰C . 
Explanation:
coefficient of linear thermal expansion of aluminum and steel is  23 x 10⁻⁶ K⁻¹ and 12 x 10⁻⁶ K⁻¹ respectively .
Rise in temperature be Δ t . 
Formula for linear expansion due to heat is as follows 
l = l₀ ( 1 + α x Δt ) 
l is expanded length , l₀ is initial length , α is coefficient of linear expansion and  Δt is increase in temperature .
For aluminum
l = 2.5 ( 1 +  23 x 10⁻⁶ Δt )
For steel 
l = 2.506 ( 1 + 12 x 10⁻⁶ Δt )
Given , 
2.5 ( 1 +  23 x 10⁻⁶ Δt ) = 2.506 ( 1 + 12 x 10⁻⁶ Δt )
 1 +  23 x 10⁻⁶ Δt = 1.0024 ( 1 + 12 x 10⁻⁶ Δt )
 1 +  23 x 10⁻⁶ Δt = 1.0024   + 12.0288 x 10⁻⁶ Δt 
10.9712 x 10⁻⁶ Δt = .0024
Δt = 218.75 
Initial temperature = 20⁰C 
final temperature = 218.75 + 20 = 238.75⁰C .