Answer: a. a leaping frog
Explanation: In a projectile motion the object must have a certain path or trajectory with respect to a certain angle. For the leaping frog its velocity can be resolve into components having the final velocity at the highest point to be zero.
A natural rock formation. Hope this helped.
Answer:
The minimum coefficient of friction required is 0.35.
Explanation:
The minimum coefficient of friction required to keep the crate from sliding can be found as follows:


Where:
μ: is the coefficient of friction
m: is the mass of the crate
g: is the gravity
a: is the acceleration of the truck
The acceleration of the truck can be found by using the following equation:


Where:
d: is the distance traveled = 46.1 m
: is the final speed of the truck = 0 (it stops)
: is the initial speed of the truck = 17.9 m/s
If we take the reference system on the crate, the force will be positive since the crate will feel the movement in the positive direction.

Therefore, the minimum coefficient of friction required is 0.35.
I hope it helps you!
39.2 J
Explanation:
Step 1:
To find the potential energy the following formula is used.
Potential Energy = m × g × h
Where,
m = Mass
g = Acceleration due to gravity
h = Height
Step 2:
Here m = 4 kg, g = 9.8 m/s², h = 1 m
Potential Energy = ( 4 × 9.8 × 1)
= 39.2 J