This depends on the direction of the velocity vector to the magnetic field vector. The force is F=q(VxB) ("x" is the cross product.) The max force is when V and B are perpendicular. Then F=qVB = (1.602e-19)(2000)(300) = 9.612e-14 N
1.5 m/s is the velocity.
9.3 m is the length of aisle, over which Distance will be covered.
Time is demanded in which the child will move the cart over the aisle with 1.5 m/s.
v=S/t
and,
t=S/v
Put values,
t=9.3/1.5=6.2 s
Answer:
The equivalent stiffness of the string is 8.93 N/m.
Explanation:
Given that,
Spring stiffness is





According to figure,
and
is in series
We need to calculate the equivalent
Using formula for series


Put the value into the formula


k and
is in parallel
We need to calculate the k'
Using formula for parallel

Put the value into the formula


,k' and
is in series
We need to calculate the equivalent stiffness of the spring
Using formula for series

Put the value into the formula


Hence, The equivalent stiffness of the string is 8.93 N/m.
Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Answer: 20.4752789138x x 10^23 atoms
To count how many atoms in moles you need to know Avogadro's number. Avogadro's number dictate that for every mole there is 6.022140857 × 10^23 molecule/atoms.
Then 3.4 moles of helium will be 3.4x 6.022140857 x 10^23 atoms= 20.4752789138x x 10^23 atoms