Answer:
Explanation:
a )
Time to reach the speed of 20 m/s with an acceleration of 2 m/s² can be calculated as follows .
v = u + a t
20 = 0 + 2 t
t = 20 /2 = 10 s .
Total time = 10 s + 20 s + 5 s = 35 s .
b) Average velocity = Total distance travelled / total time
Distance travelled in first 10 s
S₁ = ut + 1/2 a t²
= 0 + .5 x 2 x 10²
= 100 m
Distance travelled in next 20 s
S₂= 20s x 20 m/s = 400 m
Distance travelled in last 5 s .
deceleration in last 5 s
v = u + at
0 = 20 m/s + a x 5
a = - 4 m/s²
v² = u² - 2 a s
0 = (20 m/s)² - 2 x 4 m/s² x s
s = 50 m
S₃ = 50 m
Total distance = S₁ + S₂ + S₃
= 100 m + 400 m + 50 m
= 550 m .
Average velocity = 550 m / 35 s
= 15.71 m /s .
Important thing when making a lava lamp are the two liquids with different density so that it would not mix and that it would expand when heated. The movement of the orange liquid is called convection. if you will not heat the orange one, it till just stay on the stop and not go under tha water.
Answer:
a) 1111.0 seconds
b) 833.3 s
c) Because of proportions
Explanation:
a) Total time of round trip is the sum of time upriver and time downriver
Time upriver is calculated with the net speed of student and 0.500 km:
(Becareful with units 0.5 km= 500m) Similarly of downriver:
So the sum is:
b) Still water does not affect student speed, so total time would be simply:
c) For the upriver trip, student moved half the distance in half speed of the calculation in b), so it kept the same ratio and therefore, same time. So the aditional time is actually the downriver.
Answer:
Explanation:
The pulley is modelled by the Newton's Laws, whose equation of equilibrium is:
Given that tension is equal to the weight of the bucket, the angular acceleration experimented by the pulley is:
Emf e = 11
r 1 = 3.0
r 2 = 3.0
r 3 = ?
The two in parallel are equivalent to 3 • 3/6 = 1.5 Ω
To have 2.4 volts across them, the current is I = 2.4/1.5 = 1.6 amps. and the unknown R = (11–2.4) / 1.6 = 5.375 Ω or 5.4 Ω