Answer:
Explanation:
Let after time t , Tina catches up David .
Distance travelled by them are equal ,
Distance travelled by Tina
s = ut + 1/2 a t²
= .5 x 2.10 t²
= 1.05 t²
Distance travelled by David
= 30 t ( because of uniform velocity )
1.05 t² = 30t
t = 28.57 s
Distance travelled by Tina
= 1/2 a t²
= .5 x 2.10 x 28.57²
= 857 m approx.
Answer:
(a) 
(b) 
Explanation:
<u>Given:</u>
= The first temperature of air inside the tire = 
= The second temperature of air inside the tire = 
= The third temperature of air inside the tire = 
= The first volume of air inside the tire
= The second volume of air inside the tire = 
= The third volume of air inside the tire = 
= The first pressure of air inside the tire = 
<u>Assume:</u>
= The second pressure of air inside the tire
= The third pressure of air inside the tire- n = number of moles of air
Since the amount pof air inside the tire remains the same, this means the number of moles of air in the tire will remain constant.
Using ideal gas equation, we have

Part (a):
Using the above equation for this part of compression in the air, we have

Hence, the pressure in the tire after the compression is
.
Part (b):
Again using the equation for this part for the air, we have

Hence, the pressure in the tire after the car i driven at high speed is
.
Answer:
9.25 x 10^-4 Nm
Explanation:
number of turns, N = 8
major axis = 40 cm
semi major axis, a = 20 cm = 0.2 m
minor axis = 30 cm
semi minor axis, b = 15 cm = 0.15 m
current, i = 6.2 A
Magnetic field, B = 1.98 x 10^-4 T
Angle between the normal and the magnetic field is 90°.
Torque is given by
τ = N i A B SinФ
Where, A be the area of the coil.
Area of ellipse, A = π ab = 3.14 x 0.20 x 0.15 = 0.0942 m²
τ = 8 x 6.20 x 0.0942 x 1.98 x 10^-4 x Sin 90°
τ = 9.25 x 10^-4 Nm
thus, the torque is 9.25 x 10^-4 Nm.
Answer:
B
Explanation:
Potential difference has a SI Unit of Volt and its symbol is <em>V</em>. Hence answer is <u>B</u>.
A is wrong as it has the unit Joule <em>(J)</em> which is the SI unit for energy.
C is wrong as it has the unit Newton <em>(N)</em> which is the SI unit for force.
D is wrong as it has the unit Coulomb <em>(C)</em> which is the SI unit of charge.