Answer:
78.4 m
Explanation:
Using newton's equation of motion,
S = ut + 1/2gt²......................... Equation 1
Where S = Height, t = time, u = initial velocity, g = acceleration due to gravity.
Note: Taking upward to be negative, and down ward positive
Given: u = 49 m/s, t = 2.0 s, g = -9.8 m/s²
Substitute into equation 1
S = 49(2) - 1/2(9.8)(2)²
S = 98 - 19.6
S = 78.4 m
Hence the height of the ball two seconds later = 78.4 m
Answer:
Explanation:
Given
-- initial velocity
--- height
Required
Determine the time to hit the ground
This will be solved using the following motion equation.
Where
So, we have:
Subtract 30.2 from both sides
Solve using quadratic formula:
Where
Split the expression
or 
or 
Time can't be negative; So, we have:
Hence, the time to hit the ground is 1.82 seconds
Answer:
10 kg
Explanation:
The question is most likely asking for the mass of the bicycle.
Momentum is the product of an object's mass and velocity. Mathematically:
p = m * v
Where p = momentum
m = mass
v = velocity
Hence, mass is:
m = p / v
From the question:
p = 25 kgm/s
v = 2.5 m/s
Mass is:
m = 25 / 2.5 = 10 kg
The mass of the bicycle is 10 kg.
In case the question requires the Kinetic energy of the bicycle, it can be gotten by using the formula
K. E = ½ * p * v
K. E. = ½ * 25 * 2.5 = 31.25 J
<span>How many electrons would it take to equal the mass of a proton:
Here's one way of finding the value of it:
=> number of electrons is equivalent to 1 proton.
Let's have an example.
1.6726*10 -24g
_______________
1 proton
______________
9.109*10- ^28g
_______________
1 electron
Based on the given example above, the electrons is 1 839 per 1 proton.
It's about 1800 electrons/proton.</span>
