Answer:
H = 27.35 m
Explanation:
From projectile motion, we know that;
h = (v_o)²/2g
Where;
v_o = 12 m/s
g = 9.8 m/s²
Thus;
h = 12²/(2 × 9.8)
h = 144/19.6
h = 7.35 m
Now, we are told that when the man is 20 m above the pillow, he lets go of
the rope.
Thus, greatest height reached by the man above the ground is;
H = 20 + h
H = = 20 + 7.35
H = 27.35 m
(a) 392 N/m
Hook's law states that:
(1)
where
F is the force exerted on the spring
k is the spring constant
is the stretching/compression of the spring
In this problem:
- The force exerted on the spring is equal to the weight of the block attached to the spring:

- The stretching of the spring is

Solving eq.(1) for k, we find the spring constant:

(b) 17.5 cm
If a block of m = 3.0 kg is attached to the spring, the new force applied is

And so, the stretch of the spring is

And since the initial lenght of the spring is

The final length will be

Answer:
average speed is 60km/h
Explanation:
you sum up the speed attained in each distance covered and divide it by 2 to get your answer
When the velocity of an object changes, it is acted upon by a force
In a collision, there is a force on both objects that causes an acceleration of both objects; the forces are equal in magnitude and opposite in direction. For collisions between equal-mass objects, each object experiences the same acceleration.