Answer:
The speed of cart B is 11.21 m/s.
Explanation:
Given that,
Speed of cart A = 9.25 m/s
Speed of cart B = 7.15 m/s
Mass of cart A = 72.0 kg
Mass of cart B = 55.0 kg
Speed of card A after collision = 6.15 m/s
We need to calculate the speed of cart B
Using conservation of momentum

Put the value into the formula



Hence, The speed of cart B is 11.21 m/s.
 
        
             
        
        
        
Answer:
Explanation:
See the attached figure . See the forces acting on man pulling up the box . 
Man is stationary so net force acting on man is zero . 
T + R = Wman 
R is the reaction force of the ground of second floor  .
R = Wman - T 
 
        
             
        
        
        
Answer: a = 1.32 * 10^18m/s² due north 
Explanation: The magnitude of the force required to move the electron is given as 
F = ma
The force exerted on the charge by the electric field of intensity (E) is given by 
F = Eq
Thus 
Eq = ma 
a = E * q/ m
Where a = acceleration of charge 
E = strength of electric field = 7400N/c
q = magnitude of electronic charge = 1.609 * 10^-6c
m = mass of an electronic charge = 9.109 * 10^-31kg
a = 7400 * 1.609 * 10^-16/ 9.109 * 10^-31
a = 11906.6 * 10^-16 / 9.019 * 10^-31
a = 1.19 * 10^-12 / 9.019 * 10^-31
a = 0.132 * 10^19
a = 1.32 * 10^18m/s²
As stated in the question, the direction of the electric field is due north hence, the direction of it force will also be north thus making the electron experience a force due north ( according to Newton second law of motion) 
 
        
             
        
        
        
Answer:
Option C
100 J
Explanation:
Kinetic energy, KE is given by
 where m is the mass and v is the velocity
 where m is the mass and v is the velocity
Substituting 50 Kg for mass, m and 2 m/s for velocity v then we obtain

Therefore, the child's kinetic energy is equivalent to 100 J
 
        
                    
             
        
        
        
Answer:
 24.8m/s
Explanation:
Given data
m1= 10kg
u1=25m/s
m2=17kg
u2=16m/s
v1=10m/s
v2=??
Applying the conservation of linear momentum
m1u1+m2u2=m1v1+m2v2
substitute
10*25+17*16=10*10+17*v2
250+272=100+17v2
522=100+17v2
522-100=17v2
422=17v2
Divide both sides by 17
v2= 422/17
v2= 24.8 m/s
Hence the velocity of the red cart is 24.8m/s in the opposite direction of the blue cart