Answer: The minimum kinetic energy Kmin is 1.3 × 10^-13 J
Explanation: Please see the attachments below
Answer:
C
Explanation: when an object gets in front of a light, it temporarily breaks the beaks the beam from the light source to the user. the same occurs when a planet gets in front of a star. i don't feel like explaining the doppler effect but this is basically it.
hope this helped
Answer:
Explanation:
The distance of middle point from centres of spheres will be as follows
From each of 2 cm diameter sphere
R = 1 + 6.7 / 2 = 4.35 cm = 4.35 x 10⁻² m
Expression for electric field = Q / 4πε R²
Electric field due to positive charge
E₁ = 70 x 10⁻⁹ x 9 x 10⁹ / 4.35² x 10⁻⁴
= 33.3 x 10⁴ N/C
Electric field due to negative charge
E₂ = 40 x 10⁻⁹ x 9 x 10⁹ / 4.35² x 10⁻⁴
= 19.02 x 10⁴ N/C
E₁ and E₂ act in the same direction so
Total field = (33.3 + 19.02 ) x 10⁴
= 52.32 x 10⁴ N/C .
Let N be the normal force that forces the person against the wall.
Then u N = m g is the frictional force supporting the person's weight
and N = m g / u
also, N = m v^2 / R is the normal force providing the centripetal acceleration
So, m g / u = m v^2 / R
v^2 = g R / u
since v = 2 pi R T
4 pi^2 R^2 T^2 = g R / u and T^2 = g / (4 u pi^2 R)
T = 1/ (2 pi) (g /(u R))^1/2 = .159 * (9.8 m/s^2 / (.521 * 4.4 m)) ^1/2
T = .68 / s
Do you see any thing wrong here?
T should have units of seconds not 1 / seconds
v should be 2 * pi * R / T where T is the time for 1 revolution
So you need to make that correction in the above formula for v.
Answer:
Shawn's kinetic energy is 61.45 J.
Explanation:
Given;
Mass of the system is,
Displacement of the bike is,
Time taken is,
Let the constant velocity be .
For constant velocity, magnitude of velocity is given as distance by time.
Therefore,
Now, kinetic energy of a body is given as:
Here,
Therefore, Shawn's kinetic energy is 61.45 J.