Answer:
u₂ = 3.7 m/s
Explanation:
Here, we use the law of conservation of momentum, as follows:

where,
m₁ = mass of the car = 1250 kg
m₂ = mass of the truck = 2020 kg
u₁ = initial speed of the car before collision = 17.4 m/s
u₂ = initial speed of the tuck before collision = ?
v₁ = final speed of the car after collision = 6.7 m/s
v₂ = final speed of the truck after collision = 10.3 m/s
Therefore,

<u>u₂ = 3.7 m/s</u>
 
        
             
        
        
        
Answer:
Solar eclipses may be classified as either total, in which the Moon completely covers the Sun, or annular, in which the Moon obscures all but an outer ring of the Sun.
 
        
             
        
        
        
Answer:
Explanation:
mass of elephant, m1 = 5240 kg 
mass of ball, m2 = 0.150 kg 
initial velocity of elephant, u1 = - 4.55 m/s 
initial velocity of ball, u2 = 7.81 m/s 
Let the final velocity of ball is v2. 
Use the formula of collision 


v2 = - 16.9 m/s 
The negative sign shows that the ball bounces back towards you. 
(b) It is clear that the velocity of ball increases and hence the kinetic energy of the ball increases. This gain in energy is due to the energy from elephant. 
 
        
             
        
        
        
Answer:
Sonar 
Explanation:
Sonar is a technique that involves the use of sounds in viewing substances in a water medium to aid movement or communication. It makes use of the advantage of sound waves traveling faster and farther in water when compared to other types of waves such as light waves.
During World War II, the military employed the use of SONAR in imaging the seafloor by sending pulses of sound waves down through the water and measuring the time it took for the sound to bounce off the seafloor and return to the receiver.
 
        
             
        
        
        
Answer:
The incidence rate is typically expressed as the number of cases per person-year of observation. Only new cases are considered when computing the incidence rate, while cases that were diagnosed earlier are excluded. The “population at risk” measure is usually obtained from census data.
Explanation:
The incidence rate is typically expressed as the number of cases per person-year of observation. Only new cases are considered when computing the incidence rate, while cases that were diagnosed earlier are excluded. The “population at risk” measure is usually obtained from census data.