Answer:
77 Ω
Explanation:
For resistors in parallel:
1/R = 1/R₁ + 1/R₂ + 1/R₃
1/26 = 1/68 + 1/93 + 1/R₃
1/R₃ = 0.013
R₃ = 77
The resistance of R₃ is 77 Ω.
Answer:
and
Explanation:
The tub rotates at constant speed and the kinematic formula to describe the change in angular displacement (), measured in radians, is:
Where:
- Steady angular speed, measured in radians per second.
- Time, measured in seconds.
If and , then:
The change in angular displacement, measured in revolutions, is given by the following expression:
At its maximum height h, the football has zero vertical velocity, so if it was kicked with initial upward speed v, then
0² - v² = -2gh
Solve this for v :
v² = 2gh
v = √(2gh)
The height y of the football t seconds after being kicked is
y = vt - 1/2 gt²
Substitute v = √(2gh), replace y = h, and solve for h when t = 3.8 s :
h = √(2gh) t - 1/2 gt²
h = √(2gh) (3.8 s) - 1/2 g (3.8 s)²
h ≈ (16.8233 √m) √h - 70.756 m
(By √m, I mean "square root meters"; on its own this quantity doesn't make much physical sense, but we need this to be consistent with √h. h is measured in meters, so √h is measured in √m, too.)
h - (16.8233 √m) √h + 70.756 m = 0
Use the quadratic formula to solve for √h :
√h = ((16.8233 √m) ± √((16.8233 √m)² - 4 (70.756 m))) / 2
Both the positive and negative square roots result in the same solution,
√h ≈ 8.411 √m
Take the square of both sides to solve for h itself:
(√h)² ≈ (8.411 √m)²
⇒ h ≈ 70.756 m ≈ 71 m
Answer:
Explanation:
We can calculate the acceleration experimented by the passenger using the formula , taking the initial direction of movement as the positive direction and considering it comes to a rest:
Then we use Newton's 2nd Law to calculate the force the passenger of mass m experimented to have this acceleration:
Which for our values is:
answer would be C. multiply the input force.