A ball is thrown straight upward and rises to a maximum height of 18.0 m
above its launch point. at what height above its launch point has the
speed of the ball decreased to one-half of its initial value?
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kinematic equation
v^2=u^2-2as; v0=,s=18,a=-10m/s/s
u=root 360
(u/2)^2=u^2-2as
=>s=13.5m
Answer:
<h2>The answer is 90 kg</h2>
Explanation:
In order to find the mass of the football we use the formula

where
p is the momentum
v is the velocity
We have

We have the final answer as
<h3>90 kg</h3>
Hope this helps you
Answer:
The force exerted on an electron is 
Explanation:
Given that,
Charge = 3 μC
Radius a=1 m
Distance = 5 m
We need to calculate the electric field at any point on the axis of a charged ring
Using formula of electric field


Put the value into the formula


Using formula of electric field again

Put the value into the formula


We need to calculate the resultant electric field
Using formula of electric field

Put the value into the formula


We need to calculate the force exerted on an electron
Using formula of electric field


Put the value into the formula


Hence, The force exerted on an electron is 
Answer:
420000N
Explanation:
Given parameters:
Mass of the train = 5.6 x 10⁵kg
Acceleration = 0.75m/s²
Unknown:
Resultant force = ?
Solution:
According to newton's second law, force is the product of mass and acceleration;
Force = mass x acceleration
Resultant force that acts on the train is given below;
Force = 5.6 x 10⁵kg x 0.75m/s² = 420000N