Efficiency = 45J/120J = 0.375
Or
0.375 * 100% = 37.5 %
Sue from Burkey and Keith from Baron will meet in 2 minutes
Answer: Option b
<u>Explanation:</u>
Time taken can be calculated when distance and the speeds are given. Here speeds of Keith and Sue are given. So, we have to find the relative speeds in order to calculate the time taken.
When two objects travel in same direction the relative speed will be the difference between speeds. Similarly when two objects travel in opposite direction, the relative speed will be the sum of given speeds.
Given:
Speed of Sue from Burkey is 6 km/hr and speed of Keith from Baron is 3 km/hr.
The distance between Burkey and Baron is 300 m.
From the formula,
where d is distance,s is speed and t is time
It can be derived that,
s = sum of given speeds = 3 km/hr + 6 km/hr = 9 km/hr
d = 300 m = 0.3 km
To tell where things are in space
Answer:
4.38 × 10⁻³ A
0.395mΩ
452 µΩ
Explanation:
(a)the current in each strand is = the total current/ number of strand
0.876/ 200 = 4.38 × 10⁻³ A
(b) potential difference = IR
the total resistance = 2.26 µΩ × 0.876
= 0.395mΩ
c) resistance of the cable = 2.26 µΩ × 200
=452 µΩ
Answer:
(a) 1.64 rad/s²
(b) 39.94 rad
Explanation:
(a) From the question,
α = a/r................ Equation 1
Where a = linear acceleration if the motorcycle wheel, r = radius of the wheel, α = angular velocity of the wheel.
But,
a = (v-u)/t.............. Equation 2
Given: v = 1.4 m/s, u = 7.8 m/s, t = 5.8 s
Substitute into equation 2.
a = (1.4-7.8)/5.8
a = -1.1 m/s².
Note: The negative sign shows that the motorcycle is decelerating
Also given: r = 0.67 m.
Substitute into equation 1
α = 1.1/0.67
α = 1.64 rad/s²
(b)
Θ = s/r................... Equation 3
Where s = linear displacement, Θ = angular displacement.
But,
s = (v²-u²)/2a.......... Equation 2
s = (1.4²-7.8²)/[2×(-1.1)]
s = -58.88/-2.2
s = 26.76 m.
therefore,
Θ = 26.76/0.67
Θ = 39.94 rad.