Answer:
Explanation:
Assuming that cars 4 and 5 have same mass so that the momentum
P=mv where m is mass and v is velocity hence
Momentum=0+2mv+3mv=5mv
The final mass is 2m+3m=5m
From aw of conservation of momentum
hence 
Therefore, the speed is
T = tension force in the rope in upward direction
m = mass of the box attached at end of rope = 56 kg
W = weight of the box in downward direction due to gravity
a = acceleration of the box in upward direction = 5.10 m/s²
weight of the box is given as
W = mg
inserting the values
W = (56) (9.8)
W = 548.8 N
force equation for the motion of the box is given as
T - W = ma
inserting the values
T - 548.8 = (56) (5.10)
T = 834.4 N
Yes it is work because when you throw a ball, you transfer energy to it and it moves.
Work done = 0.5*m*[(v2)^2 - (v1)^2]
where m is mass,
v2 and v1 are the velocities.
Given that m = 1.50 x 10^3 kg, v2 = -15 m/s (decelerates), v1 = 25 kg,
Work done = 0.5 * 1.50 x 10^3 * ((-15)^2 - 25^2) = 3 x 10^5 joules
Just ignore the negative value for the final result because work is a scalar quantity.
