Let the key is free falling, therefore from equation of motion
.
Take initial velocity, u=0, so
.

As velocity moves with constant velocity of 3.5 m/s, therefore we can use formula

From above substituting t,
.
Now substituting all the given values and g = 9.8 m/s^2, we get
.
Thus, the distance the boat was from the point of impact when the key was released is 10.60 m.
Answer:
14 m/s
Explanation:
u = 0, h = 10 m, g = 9.8 m/s^2
Use third equation of motion
v^2 = u^2 + 2 g h
Here, v be the velocity of ball as it just strikes with the ground
v^2 = 0 + 2 x 9.8 x 10
v^2 = 196
v = 14 m/s
The annual production of carbon dioxide is 124121.49×10^{6}[/tex] kg.
First we calculate the fuel consumed by each car in a year
Fuel consumed=6990/21.4=326.63 gallon
Now we calculate the amount of fuel consumed by 40 million cars in a year
Fuel consumed=326.63*40*10^6=13065.42 million gallon,
Now we can calculate the annual production of carbon dioxide in the USA
CO2 production rate=9.50*13065.42=124121.49*10^6 kg
Therefore the annual production of carbon dioxide in USA is 124121.49×10^{6}[/tex] kg
If the object is in equilibrium that means that the sum of the forces on it is zero and the net force is zero. If none of the forces changes then the object continues in constant uniform motion. That means constant speed in a straight line.