Bar magnets have 2 poles. I think. Answer: first choice
Answer:
2*10^9electrons
Explanation:
Remember that the net force will be zero at terminal voltege so
Mg = 6πrng
At 35v
We have
qvr = 6πrng
q= 6 x 3.142* nx 2.6*10^-5/35
q,= 3.2x 10^ - 10C
So using n= q/e
= 3.2x 10^ - 10C/1.6*10-19
= 2*10^9electrons
7.5m/s (2.5 x 3) c = frequency x wavelength
Answer:
speed when it reaches y = 4.00cm is
v = 14.9 g.m/s
Explanation:
given
q₁=q₂ =2.00 ×10⁻⁶
distance along x = 3.00cm= 3×10⁻²
q₃= 4×10⁻⁶C
mass= 10×10 ⁻³g
distance along y = 4×10⁻²m
r₁ = 
= 
= 3.61cm = 0.036m
r₂ = 
= 
= 5cm = 0.05m
electric potential V = 
change in potential ΔV = 
ΔV = 
, where 
2.00μC
ΔV = 
ΔV = 2 × 9×10⁹ × 2×10⁻⁶ × 
ΔV= 2.789×10⁵
= ΔV × q₃
ˣ 10×10⁻³ ×v² = 2.789×10⁵× 4 ×10⁻⁶
v² = 223.12 g.m/s
v = 14.9 g.m/s
Answer:
<h2>a.The ball's vertical acceleration is downwards.</h2><h2>e.The ball's horizontal acceleration is zero</h2>
Explanation:
We are given that Sarah throws a tennis ball as far as she can.
At the moment the ball reaches its maximum height.
We have to find the true statement if air resistance is neglect.
When air resistance is negligible then the force act on the ball is force due to gravity.
The ball throw vertically then the acceleration act on the ball is acceleration due to gravity.
The value of g=-9.8 m/square sec
It acts on the ball in downward direction .
Therefore, the ball's vertical acceleration is downwards.
The horizontal acceleration is zero because the ball reaches at maximum height then there is no force which act in horizontal direction on the ball.
Therefore, horizontal acceleration of the ball is zero.
Hence, option a and e are true.
