Answer:
The speed with which the baseball leaves the hand = 20.58 m/s
Explanation:
The time take to reach highest height during a projectile's flight is given by
t = (u sin θ)/g
u = initial velocity of the baseball = ?
θ = angle of throw above the horizontal
g = acceleration due to gravity = 9.8 m/s²
1.05 = (u sin 30)/9.8
u = (1.05 × 9.8)/0.5
u = 20.58 m/s
Answer:
THE FIRST ONE YOU SHOULD TELL HIM AND THE LAST ONE YOU SHOUDENT DO BECAUSE HE WILL DO IT AGAIN AND EXPECT OTHERS TO CLEAN UP AFTER HIM
Explanation:
Answer:
ΔH°comb=-5899.5 kJ/mol
Explanation:
First, consider the energy balance:
Where
is the calorimeter mass and
is the number of moles of the samples;
is the combustion enthalpy. The energy balance says that the energy that the reaction release is employed in rise the temperature of the calorimeter, which is designed to be adiabatic, so it is suppose that the total energy is employed rising the calorimeter temperature.
The product
is the heat capacity, so the balance equation is:

So, the enthalpy of combustion can be calculated:

I will be happy to solve any doubt you have.
Answer:

Explanation:
It is given that,
Mass of the puck, m = 4.8 kg
Initial velocity of the puck, 
After 8 seconds, final velocity of the puck, 
Let the x and y component of force is given by
.
x component of force is given by :


y component of force is given by :


So, the component of the force is
. Hence, this is the required solution.
Using the given formula with v0=56 ft/s and h=40 ft
h = -16t2 + v0t
40 = -16t2 + 56t
16t2 - 56t + 40 = 0
Solving the quadratic equation:
t= (-b+/-(b^2-4ac)^1/2)/2a = (56+/-((-56)^2-4*16*40)^1/2)/2*16 = (56 +/- 24) / 32
We have two possible solutions
t1 = (56+24)/32 = 2.5
t2 = (56-24)/32 = 1
So initially the ball reach a height of 40 ft in 1 second.