Given
The projectile is in air for a time of t=8 sec
To find
The time it takes to reach the highest point
Explanation
A projectile moves up to the highest point and then again moves down following a parabolic path.
So it will reach the highest point at a time half the time it requires to follow teh parabolic path.
The time taken to reach the highest point is 4 sec
Conclusion
The time taken is 4 sec.
Answer:
1.736m/s²
Explanation:
According to Newton's second law;

where;
Fm is the moving force = 70.0N
Ff is the frictional force acting on the body

is the coefficient of friction
m is the mass of the object
g is the acceleration due to gravity
a is the acceleration/deceleration
The equation becomes;

Substitute the given parameters

Hence the deceleration rate of the wagon as it is caught is 1.736m/s²
A negative to a negative charge will make a neutral charge.