Answer:
the tension in the string an instant before it broke = 34 N
Explanation:
Given that :
mass of the ball m = 300 g = 0.300 kg
length of the string r = 70 cm = 0.7 m
At highest point, law of conservation of energy can be expressed as :
The tension in the string is:
Thus, the tension in the string an instant before it broke = 34 N
Answer:
B 14.5 m/s to the east
Explanation:
We can solve this problem by using the law of conservation of momentum.
In fact, if the system is isolated, the total momentum of the system must be conserved.
Here the total momentum before the stuntman reaches the skateboard is:
where
M = 72.0 kg is the mass of the stuntman
v = 15.0 m/s is his initial velocity (to the east)
The total momentum after the stuntmen reaches the skateboard is:
where
m = 2.50 kg is the mass of the skateboard
v' is the final velocity of the stuntman and the skateboard
Since momentum must be conserved, we have
And solvign for v',
And since the sign is the same as v, the direction is the same (to the east).