Answer:
<em>1.187 x 10^8 m/s</em>
<em></em>
Explanation:
the potential of the electric field V = 40 kV = 40000 V
the charge on an electron e = 1.6 x 10^-19 C
The energy of an accelerated electron in an electric field is given as
E = eV
E = 1.6 x 10^-19 x 40000 = 6.4 x 10^-15 J
This energy is equal to the kinetic energy with which the electron moves, according to the conservation of energy.
The kinetic energy = 
where
m is the mass of the electron = 9.109 x 10^-31
v is the speed of the electron.
Equating the energy, we have
6.4 x 10^-15 = 
6.4 x 10^-15 = 4.55 x 10^-31 
= 1.41 x 10^16
= <em>1.187 x 10^8 m/s</em>
The force exerted on the board by the karate master given the data is -4500 N
<h3>Data obtained from the question </h3>
- Initial velocity (u) = 10 m/s
- Final velocity (v) = 1 m/s
- Time (t) = 0.002 s
- Mass (m) = 1 Kg
- Force (F) = ?
<h3>How to determine the force</h3>
The force exerted can be obtained as illustrated below:
F = m(v - u) / t
F = 1 (1 - 10) / 0.002
F = (1 × -9) / 0.002
F = -4500 N
Learn more about momentum:
brainly.com/question/250648
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Answer:
<h2>
200m/min</h2>
Explanation:
The formula for calculating distance covered = Speed * time
If Maggie completed a 10000-m race at an average speed of 160
m/min, the the time taken by Maggie to complete the race will be expressed as;
Time = Distance/Speed
Time = 10000/160
Time = 62.5 minutes
If it took Tom 12.5 fewer minutes to complete the race, then the time taken by tom to finish the same race will be 62.5 - 12.5 = 50minutes.
To get Tom's average speed, we will use the same formula as above;
From Distance = Speed * Time
Speed = Distance/Time
Since both of them completed the same distance, distance covered by Tom is also 10000m
Tom's speed = 10000/50
Tom's speed = 200m/min
<em>Hence Tom's average speed is 200m/min</em>
Answer:
Explanation:
The wheel and falling student will have common acceleration .
For rotational motion of wheel
Tx r = I α , T is tension in the crank , α is angular acceleration of wheel , I is moment of inertia , r is radius of the wheel.
= I a / r
T = I a / r²
For motion of student
Mg - T = Ma , M is mass of the wheel.
Mg - I a / r² = Ma
Mg = Ma +I a / r²
Mg = (M +I / r²)a
a = Mg / (M +I / r²)
= 51 x 9.8 / ( 51 + 9.6 / .3² )
499.8 / (51+ 106.67 )
= 499.8 / 157.67
= 3.17 m / s².
If time t is taken to fall by 12 m
12 = 1/2 a t²
24 / a = t²
24 / 3.17 =t²
t²= 7.57
t = 2.75 s
velocity to reach sidewalk
v = u + at
= 3.17 x 2.75
= 8.72 m / s
