Answer:
a) The speed of the block immediately after the collision is
.
b) The impulse exerted on the block is
.
Explanation:
Hi
a) As this is a perfectly elastic collision, we can use the formula
, due
, we obtain
. Then with the data that we know
and
, therefore
or
adding uncertainty.
b) Now that we know the speed we can use 
Answer:

Explanation:
a = Orbital radius = 
T = Orbital period = 23.21 hours
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
From Kepler's third law we get

From the given data the mass of Saturn is 
The answer is the fourth choice because there are 7 represents in a coefficient.
A good answer is a giraffe and a tree