Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :
Where
s is the height in feet
For the given condition, the equation becomes:
When it hits the ground, h = 0
i.e.
It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
The answer is B. Unbalanced force
Answer:
Reduce the friction at the surface
Explanation:
If you can reduce the friction between the load and the plane less effort will be required as you are not having to apply effort to overcome friction.
Answer:
Q = 282,000 J
Explanation:
Given that,
The mass of liquid water, m = 125 g
Temperature, T = 100°C
The latent heat of vaporization, Hv = 2258 J/g.
We need to find the amount of heat needed to vaporize 125 g of liquid water. We can find it as follows :
or
Q = 282,000 J
So, the required heat is 282,000 J
.
