Hi:) anyone able to help with the last part? Thanks!:)

t=50s

Explanation:

For speed-time graphs, the distance traveled can be found by finding the area under the graph.

When the 2 cars meet, the distance travelled by both of them would be equal.

Let's find the distance travelled by car A at t=40s.

Area of traingle= ½( base)( height)

Distance by Car A at t=40s

= ½(40)(20)

= 400m

Distance by Car B at 40s

= ½(20)(15) +20(15)

= 150 +300

= 450m

Difference in distance= 50m

From t=40s onwards, the cars travels at a constant speed and the increase in their total distance would be at a constant rate.

For every 20s, car A would travel an additional 20(20)= 400m. And car B would travel an additional 15(20)= 300m.

Hence for every 20s, the distance between the 2 cars would decrease by 400 -300= 100m. Thus, for 50m, additional time needed (from t=40s)= ½(20)= 10s.

Since to closen the gap by 100m, 20s is needed.

100m 20s

50m 20 ÷2= 10s

Therefore the cars would meet again 10s after t=40s, which is at t=50s.

Let's check!

At t=50s,

Distance travelled by Car A

= ½(40)(20) +10(20)

= 400 +200

= 600m

Distance travelled by Car B

= ½(20)(15) + 30(15)

= 150 +450

= 600m

✓ Both travelled an equal distance of 600m at t=50s.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: